diff --git a/example.yaml b/example.yaml
index 051c3f2..1608adb 100644
--- a/example.yaml
+++ b/example.yaml
@@ -1,14 +1,18 @@
 dest: /path/to/store/backup/files  # The programs will store database and backup files in this location
+remove_old_files: true  # Optional. Default value: true. Remove unneeded backup files which already deleted in source tree when backuping files.
 programs:
   - name: Your program name  # This name is used to identify different application.
     base: /path/to/save/path  # Must be absoulte path.
+    remove_old_files: true  # Optional.
     files:
       - BGI.gdb  # path to a file/folder. All subfolders will include if it is a folder. Must be relative path.
       - type: path
         path: folder  # path to a file/folder. All subfolders will include if it is a folder. Must be relative path if name not found.
         name: folder2  # optional. path to the backup files. Shoule be a relative path
+        remove_old_files: true  # Optional.
       - type: leveldb  # module plyvel is needed to support this type. This will store leveldb database to a single file database (sqlite3)
         path: leveldb  # path to leveldb. Must be relative path.
         name: dest  # optional. path to the backup files. Shoule be a relative path
+        remove_old_files: true  # Optional.
         domains:  # optional. Just backup minor domains in localstorage database. Only chromium is tested.
           - some domain
diff --git a/game_backuper/backuper.py b/game_backuper/backuper.py
index 04e3482..9d4cc12 100644
--- a/game_backuper/backuper.py
+++ b/game_backuper/backuper.py
@@ -26,9 +26,12 @@ class BackupTask(Thread):
         bp = join(self.cfg.dest, prog)
         if not exists(bp):
             mkdir(bp)
+        fl = self.db.get_file_list(prog)
         for f in self.prog.files:
             if isinstance(f, ConfigNormalFile):
                 if exists(f[1]):
+                    if f.name in fl:
+                        fl.remove(f.name)
                     ori = self.db.get_file(prog, f[0])
                     nf = new_file(f[1], f[0], prog)
                     if nf is None:
@@ -49,6 +52,8 @@ class BackupTask(Thread):
                     raise NotImplementedError('Leveldb is not supported.')
                 if not exists(f.full_path):
                     continue
+                if f.name in fl:
+                    fl.remove(f.name)
                 from game_backuper.leveldb import (
                     list_leveldb_entries,
                     leveldb_stats,
@@ -79,6 +84,20 @@ class BackupTask(Thread):
                     self.db.add_file(nf)
                 else:
                     self.db.set_file(ori.id, stats.size, stats.hash)
+        for fn in fl:
+            f = self.db.get_file(prog, fn)
+            if f.type is None:
+                de = join(bp, fn)
+                if exists(de):
+                    remove(de)
+                    print(f'{prog}: Remove {de}({fn})')
+                self.db.remove_file(f)
+            if f.type == FileType.LEVELDB:
+                de = join(bp, fn + '.db')
+                if exists(de):
+                    remove(de)
+                    print(f'{prog}: Remove {de}({fn})')
+                self.db.remove_file(f)
 
 
 class Backuper:
diff --git a/game_backuper/config.py b/game_backuper/config.py
index 50133c9..6e337e4 100644
--- a/game_backuper/config.py
+++ b/game_backuper/config.py
@@ -7,19 +7,62 @@ from os.path import join, relpath, isfile, isdir, isabs
 from typing import List, Union
 from game_backuper.file import listdirs
 from collections import namedtuple
+try:
+    from functools import cached_property
+except ImportError:
+    cached_property = property
 
 
-ConfigNormalFile = namedtuple('ConfigNormalFile', ['name', 'full_path'])
-ConfigLeveldb = namedtuple('ConfigLeveldb', ['name', 'full_path', 'domains'])
+class BasicOption:
+    _remove_old_files = None
+
+    @cached_property
+    def remove_old_files(self) -> bool:
+        if self._remove_old_files is not None:
+            return self._remove_old_files
+        prog = getattr(self, "_prog", None)
+        if prog is not None:
+            if prog._remove_old_files is not None:
+                return prog._remove_old_files
+        cfg = getattr(self, "_cfg", None)
+        if cfg is not None:
+            if cfg._remove_old_files is not None:
+                return cfg._remove_old_files
+        return True
+
+    def parse_all(self, data=None):
+        self.parse_remove_old_files(data)
+
+    def parse_remove_old_files(self, data=None):
+        if data is None:
+            data = getattr(self, 'data')
+        if 'remove_old_files' in data:
+            v = data['remove_old_files']
+            if isinstance(v, bool):
+                self._remove_old_files = v
+            else:
+                raise TypeError('remove_old_files option must be a boolean.')
+            del v
+
+
+def namedtuple_bo(typename, field_names):
+    a = namedtuple(typename, field_names)
+    return type(typename, (a, BasicOption), {})
+
+
+ConfigNormalFile = namedtuple_bo('ConfigNormalFile', ['name', 'full_path'])
+ConfigLeveldb = namedtuple_bo('ConfigLeveldb', ['name', 'full_path', 'domains'])  # noqa: E501
 ConfigResult = Union[ConfigNormalFile, ConfigLeveldb]
 
 
-class Program:
-    def __init__(self, data: dict):
+class Program(BasicOption):
+    def __init__(self, data: dict, cfg):
         self.data = data
         self._files = None
+        self._cfg = cfg
+        self.parse_all()
 
-    @property
+    @cached_property
     def base(self) -> str:
         if 'base' in self.data:
             v = self.data['base']
@@ -71,11 +114,15 @@ class Program:
                             if i['name'] != '':
                                 name = i['name']
                     if isfile(bp):
-                        r.append(ConfigNormalFile(name, bp))
+                        tmp = ConfigNormalFile(name, bp)
+                        tmp.parse_all(i)
+                        r.append(tmp)
                     elif isdir(bp):
                         ll = listdirs(bp)
                         for ii in ll:
-                            r.append(ConfigNormalFile(join(name, relpath(ii, bp)), ii))  # noqa: E501
+                            tmp = ConfigNormalFile(join(name, relpath(ii, bp)), ii)  # noqa: E501
+                            tmp.parse_all(i)
+                            r.append(tmp)
                 elif t == 'leveldb':
                     if isabs(i['path']):
                         if 'name' not in i or not isinstance(i['name'], str) or i['name'] == '':  # noqa: E501
@@ -96,10 +143,14 @@ class Program:
                                 dms.append(ii.encode())
                         if len(dms) == 0:
                             dms = None
-                    r.append(ConfigLeveldb(n, p, dms))
+                    tmp = ConfigLeveldb(n, p, dms)
+                    tmp.parse_all(i)
+                    r.append(tmp)
+        for i in r:
+            i._prog = self
         return r
 
-    @property
+    @cached_property
     def name(self) -> str:
         if 'name' in self.data:
             v = self.data['name']
@@ -107,7 +158,7 @@ class Program:
                 return v
 
 
-class Config:
+class Config(BasicOption):
     dest = ''
     progs = []
     progs_name = []
@@ -124,11 +175,12 @@ class Config:
         self.dest = t['dest']
         if 'programs' not in t:
             raise ValueError("No programs found.")
+        self.parse_all(t)
         progs = t['programs']
         if not isinstance(progs, list):
             raise ValueError("programs should be list.")
         for prog in progs:
-            p = Program(prog)
+            p = Program(prog, self)
             if not p.check():
                 raise ValueError('Config error: program information error')
             if p.name not in self.progs_name:
diff --git a/game_backuper/db.py b/game_backuper/db.py
index 73df339..67db77f 100644
--- a/game_backuper/db.py
+++ b/game_backuper/db.py
@@ -111,6 +111,15 @@ class Db:
             for i in cur:
                 return File(*i)
 
+    def get_file_list(self, prog: str) -> List[str]:
+        with self._lock:
+            cur = self.db.execute('SELECT file FROM files WHERE program=?;',
+                                  (prog,))
+            li = []
+            for i in cur:
+                li.append(i[0])
+            return li
+
     def remove_file(self, id: Union[int, File]):
         with self._lock:
             ft = None