Data change marking device

The invention discloses a data change marking device which comprises a storage, a searcher and an encoder. After a root object and a subobject are scanned by the searcher, marking is performed on the scanning fixing marker bits of the root object and the subobject; after attributes of the root object or the subobject are changed, the root object or the subobject with the attributes changed is encoded through the encoder, and marking is performed on changed fixing marker bits of the root object or the subobject with the attributes changed; and when an object is newly increased, marking is performed on one newly increased fixing marker bit of the newly increased newly increased at the encoding stage through the encoder.