diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6a9fc6d..ee0f79c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -146,6 +146,8 @@ set(SOURCE_FILE_HEADERS
     stack.h
     linked_stack.h
     circular_queue.h
+    binary_tree.h
+    binary_search_tree.h
 )
 
 if (NOT HAVE_STRPTIME)
@@ -195,7 +197,7 @@ if (ENABLE_UTILS_TESTING)
     set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
     add_subdirectory(googletest)
     enable_testing()
-    add_executable(unittest test/stack_test.cpp test/queue_test.cpp)
+    add_executable(unittest test/stack_test.cpp test/queue_test.cpp test/binary_tree_test.cpp)
     target_link_libraries(unittest GTest::gtest_main utils)
     include(GoogleTest)
     gtest_discover_tests(unittest)
diff --git a/binary_search_tree.h b/binary_search_tree.h
new file mode 100644
index 0000000..2179f72
--- /dev/null
+++ b/binary_search_tree.h
@@ -0,0 +1,96 @@
+#ifndef _UTIL_BINARY_SEARCH_TREE_H
+#define _UTIL_BINARY_SEARCH_TREE_H
+#include "binary_tree.h"
+
+template <typename K, typename V>
+struct BinarySearchTreePair {
+    K key;
+    V value;
+};
+
+template <typename K, typename V>
+using BinarySearchTree = BinaryTree<BinarySearchTreePair<K, V>>;
+
+template <typename K, typename V>
+void binary_search_tree_clear(BinarySearchTree<K, V>*& root, std::function<void(K)> free_key = std::function<void(K)>(), std::function<void(V)> free_value = std::function<void(V)>()) {
+    if (free_key || free_value) {
+        binary_tree_clear(root, [&free_key, &free_value](BinarySearchTreePair<K, V> e) {
+            if (free_key) free_key(e.key);
+            if (free_value) free_value(e.value);
+        });
+    } else {
+        binary_tree_clear(root);
+    }
+}
+
+template <typename K, typename V, class F, class G>
+inline void binary_search_tree_clear(BinarySearchTree<K, V>*& root, F free_key, G free_value = nullptr) {
+    binary_search_tree_clear(root, std::function<void(K)>(free_key), std::function<void(V)>(free_value));
+}
+
+template <typename K, typename V, typename... Args>
+void binary_search_tree_iter(BinarySearchTree<K, V>* root, std::function<void(K, V, Args...)> callback, Args... args) {
+    binary_tree_lnr(root, [&callback](BinarySearchTree<K, V>* e, Args... args) {
+        callback(e->data.key, e->data.value, args...);
+    }, args...);
+}
+
+template <typename K, typename V, class F, typename... Args>
+inline void binary_search_tree_iter(BinarySearchTree<K, V>* root, F callback, Args... args) {
+    binary_search_tree_iter(root, std::function<void(K, V, Args...)>(callback), args...);
+}
+
+template <typename K, typename V>
+bool binary_search_tree_insert(BinarySearchTree<K, V>*& root, K key, V value, std::function<int(K, K)> comp, std::function<void(K)> free_key = std::function<void(K)>(), std::function<void(V)> free_value = std::function<void(V)>()) {
+    if (!root) {
+        root = binary_tree_new<BinarySearchTreePair<K, V>>({ key, value });
+        if (!root) {
+            if (free_key) free_key(key);
+            if (free_value) free_value(value);
+        }
+        return root != nullptr;
+    }
+    BinarySearchTree<K, V>* cur = root;
+    int re = comp(key, cur->data.key);
+    while (!binary_tree_is_leaf(cur)) {
+        if (re == 0) {
+            break;
+        }
+        if (re < 0 && !cur->left) break;
+        if (re > 0 && !cur->right) break;
+        cur = re < 0 ? cur->left : cur->right;
+        re = comp(key, cur->data.key);
+    }
+    if (re == 0) {
+        if (free_value) free_value(cur->data.value);
+        if (free_key) free_key(key);
+        cur->data.value = value;
+        return true;
+    }
+    BinarySearchTree<K, V>* node = binary_tree_new<BinarySearchTreePair<K, V>>({key, value});
+    if (!node) {
+        if (free_key) free_key(key);
+        if (free_value) free_value(value);
+        return false;
+    }
+    if (re == -1) {
+        cur->left = node;
+    } else {
+        cur->right = node;
+    }
+    return true;
+}
+
+template <typename K, typename V, class F>
+inline bool binary_search_tree_insert(BinarySearchTree<K, V>*& root, K key, V value, F comp) {
+    return binary_search_tree_insert(root, key, value, std::function<int(K, K)>(comp));
+}
+
+template <typename K, typename V>
+bool binary_search_tree_insert(BinarySearchTree<K, V>*& root, K key, V value) {
+    return binary_search_tree_insert(root, key, value, [](K k1, K k2) {
+        return k1 == k2 ? 0 : k1 < k2 ? -1 : 1;
+    });
+}
+
+#endif
diff --git a/binary_tree.h b/binary_tree.h
new file mode 100644
index 0000000..2a3d410
--- /dev/null
+++ b/binary_tree.h
@@ -0,0 +1,115 @@
+#ifndef _UTIL_BINARY_TREE_H
+#define _UTIL_BINARY_TREE_H
+#include <functional>
+#include <stddef.h>
+#include <malloc.h>
+#include <string.h>
+#include "linked_queue.h"
+
+template <typename T>
+struct BinaryTree {
+    T data;
+    struct BinaryTree* left;
+    struct BinaryTree* right;
+};
+
+template <typename T>
+void binary_tree_clear(struct BinaryTree<T>*& top, std::function<void(T)> free_func = std::function<void(T)>()) {
+    if (!top) return;
+    binary_tree_dfs(top, [&free_func](struct BinaryTree<T>* node) {
+        if (free_func) {
+            free_func(node->data);
+        }
+        node->left = nullptr;
+        node->right = nullptr;
+        free(node);
+    });
+    top = nullptr;
+}
+
+template <typename T, class F>
+inline void binary_tree_clear(struct BinaryTree<T>*& top, F free_func) {
+    binary_tree_clear(top, std::function<void(T)>(free_func));
+}
+
+template <typename T, typename... Args>
+void binary_tree_dfs(struct BinaryTree<T>* top, std::function<void(struct BinaryTree<T>*, Args...)> callback, Args... args) {
+    if (!top) return;
+    if (top->left) binary_tree_dfs(top->left, callback, args...);
+    if (top->right) binary_tree_dfs(top->right, callback, args...);
+    callback(top, args...);
+}
+
+template <typename T, class F, typename... Args>
+inline void binary_tree_dfs(struct BinaryTree<T>* top, F callback, Args... args) {
+    binary_tree_dfs(top, std::function<void(struct BinaryTree<T>*, Args...)>(callback), args...);
+}
+
+#define binary_tree_lrn binary_tree_dfs
+
+template <typename T, typename... Args>
+void binary_tree_lnr(struct BinaryTree<T>* top, std::function<void(struct BinaryTree<T>*, Args...)> callback, Args... args) {
+    if (!top) return;
+    if (top->left) binary_tree_lnr(top->left, callback, args...);
+    callback(top, args...);
+    if (top->right) binary_tree_lnr(top->right, callback, args...);
+}
+
+template <typename T, class F, typename... Args>
+inline void binary_tree_lnr(struct BinaryTree<T>* top, F callback, Args... args) {
+    binary_tree_lnr(top, std::function<void(struct BinaryTree<T>*, Args...)>(callback), args...);
+}
+
+template <typename T, typename... Args>
+void binary_tree_nlr(struct BinaryTree<T>* top, std::function<void(struct BinaryTree<T>*, Args...)> callback, Args... args) {
+    if (!top) return;
+    callback(top, args...);
+    if (top->left) binary_tree_nlr(top->left, callback, args...);
+    if (top->right) binary_tree_nlr(top->right, callback, args...);
+}
+
+template <typename T, class F, typename... Args>
+inline void binary_tree_nlr(struct BinaryTree<T>* top, F callback, Args... args) {
+    binary_tree_nlr(top, std::function<void(struct BinaryTree<T>*, Args...)>(callback), args...);
+}
+
+template <typename T, typename... Args>
+void binary_tree_bfs(struct BinaryTree<T>* top, std::function<void(struct BinaryTree<T>*, Args...)> callback, Args... args) {
+    if (!top) return;
+    struct LinkedQueue<struct BinaryTree<T>*> queue;
+    linked_queue_init(queue);
+    linked_queue_push(queue, top);
+    struct BinaryTree<T>* tmp;
+    while (linked_queue_pop(queue, tmp)) {
+        if (tmp->left) linked_queue_push(queue, tmp->left);
+        if (tmp->right) linked_queue_push(queue, tmp->right);
+        callback(tmp, args...);
+    }
+}
+
+template <typename T, class F, typename... Args>
+inline void binary_tree_bfs(struct BinaryTree<T>* top, F callback, Args... args) {
+    binary_tree_bfs(top, std::function<void(struct BinaryTree<T>*, Args...)>(callback), args...);
+}
+
+template <typename T>
+struct BinaryTree<T>* binary_tree_new(T data) {
+    struct BinaryTree<T>* node = (struct BinaryTree<T>*)malloc(sizeof(struct BinaryTree<T>));
+    if (!node) return nullptr;
+    node->data = data;
+    node->left = nullptr;
+    node->right = nullptr;
+    return node;
+}
+
+template <typename T>
+inline bool binary_tree_is_leaf(struct BinaryTree<T>* node) {
+    return node->left == nullptr && node->right == nullptr;
+}
+
+template <typename T>
+inline bool binary_tree_node_is_full(struct BinaryTree<T>* node) {
+    return node->left != nullptr && node->right != nullptr;
+}
+
+#endif
diff --git a/linked_queue.h b/linked_queue.h
index 4c1297a..256227e 100644
--- a/linked_queue.h
+++ b/linked_queue.h
@@ -16,6 +16,12 @@ struct LinkedQueue {
     struct LinkedQueueNode<T>* rear;
 };
 
+template <typename T>
+void linked_queue_init(struct LinkedQueue<T>& queue) {
+    queue.front = nullptr;
+    queue.rear = nullptr;
+}
+
 template <typename T>
 size_t linked_queue_length(struct LinkedQueue<T>& queue) {
     if (!queue.front) return 0;
diff --git a/test/binary_tree_test.cpp b/test/binary_tree_test.cpp
new file mode 100644
index 0000000..71295a8
--- /dev/null
+++ b/test/binary_tree_test.cpp
@@ -0,0 +1,72 @@
+#include "gtest/gtest.h"
+#include "binary_search_tree.h"
+#include <string>
+
+TEST(BinaryTreeTest, BinaryTree1) {
+    struct BinaryTree<int>* top = binary_tree_new(1);
+    top->left = binary_tree_new(2);
+    top->right = binary_tree_new(3);
+    top->left->left = binary_tree_new(4);
+    top->left->right = binary_tree_new(5);
+    top->right->right = binary_tree_new(6);
+    std::string text;
+    binary_tree_dfs(top, [&text](struct BinaryTree<int>* ele) {
+        if (!text.empty()) {
+            text += ",";
+        }
+        text += std::to_string(ele->data);
+    });
+    GTEST_ASSERT_EQ(text, "4,5,2,6,3,1");
+    text = "";
+    binary_tree_lnr(top, [&text](struct BinaryTree<int>* ele) {
+        if (!text.empty()) {
+            text += ",";
+        }
+        text += std::to_string(ele->data);
+    });
+    GTEST_ASSERT_EQ(text, "4,2,5,1,3,6");
+    text = "";
+    binary_tree_nlr(top, [&text](struct BinaryTree<int>* ele) {
+        if (!text.empty()) {
+            text += ",";
+        }
+        text += std::to_string(ele->data);
+    });
+    GTEST_ASSERT_EQ(text, "1,2,4,5,3,6");
+    text = "";
+    binary_tree_bfs(top, [&text](struct BinaryTree<int>* ele) {
+        if (!text.empty()) {
+            text += ",";
+        }
+        text += std::to_string(ele->data);
+    });
+    GTEST_ASSERT_EQ(text, "1,2,3,4,5,6");
+    binary_tree_clear(top);
+}
+
+TEST(BinaryTreeTest, BinarySearchTree1) {
+    BinarySearchTree<int, int>* tree = nullptr;
+    binary_search_tree_insert(tree, 100, 3);
+    GTEST_ASSERT_EQ(tree->data.key, 100);
+    GTEST_ASSERT_EQ(tree->data.value, 3);
+    binary_search_tree_insert(tree, 100, 20);
+    GTEST_ASSERT_EQ(tree->data.value, 20);
+    binary_search_tree_insert(tree, 20, 45);
+    binary_search_tree_insert(tree, 40, 13);
+    binary_search_tree_insert(tree, 33, 23);
+    binary_search_tree_insert(tree, 77, 33);
+    binary_search_tree_insert(tree, 120, 222);
+    std::string keys;
+    std::string values;
+    binary_search_tree_iter(tree, [&keys, &values](int key, int value) {
+        if (!keys.empty()) {
+            keys += ",";
+            values += ",";
+        }
+        keys += std::to_string(key);
+        values += std::to_string(value);
+    });
+    GTEST_ASSERT_EQ(keys, "20,33,40,77,100,120");
+    GTEST_ASSERT_EQ(values, "45,23,13,33,20,222");
+    binary_search_tree_clear(tree);
+}
diff --git a/test/queue_test.cpp b/test/queue_test.cpp
index 30a65e6..fc9ab36 100644
--- a/test/queue_test.cpp
+++ b/test/queue_test.cpp
@@ -85,8 +85,7 @@ TEST(Queue_Test, CircularQueue2) {
 
 TEST(Queue_Test, LinkedQueue1) {
     struct LinkedQueue<int> queue;
-    queue.front = nullptr;
-    queue.rear = nullptr;
+    linked_queue_init(queue);
     EXPECT_EQ(linked_queue_push(queue, 3), true);
     EXPECT_EQ(linked_queue_push(queue, 4), true);
     EXPECT_EQ(linked_queue_push(queue, 9), true);
@@ -105,3 +104,20 @@ TEST(Queue_Test, LinkedQueue1) {
     EXPECT_EQ(text, "4,9,7");
     free_linked_queue(queue);
 }
+
+TEST(Queue_Test, LinkedQueue2) {
+    struct LinkedQueue<int> queue;
+    linked_queue_init(queue);
+    EXPECT_EQ(linked_queue_push(queue, 3), true);
+    EXPECT_EQ(linked_queue_push(queue, 4), true);
+    EXPECT_EQ(linked_queue_push(queue, 9), true);
+     int v;
+    EXPECT_EQ(linked_queue_pop(queue, v), true);
+    EXPECT_EQ(v, 3);
+    EXPECT_EQ(linked_queue_pop(queue, v), true);
+    EXPECT_EQ(linked_queue_pop(queue, v), true);
+    EXPECT_EQ(linked_queue_pop(queue, v), false);
+    EXPECT_EQ(v, 9);
+    EXPECT_EQ(queue.front, nullptr);
+    EXPECT_EQ(queue.rear, nullptr);
+}