A document management system includes a storage section, a reference electronic manuscript acquisition section, an edit part identification section and a document editing processing section. The storage section stores at least one of an electronic manuscript and an electronic document generated by combining plural electronic manuscripts. The reference electronic manuscript acquisition section acquires a reference electronic manuscript used for identifying a reference position of an edit part in an edit electronic document that is an electronic document to be edited and is read from the storage section. The edit part identification section identifies the edit part in the edit electronic document based on the reference electronic manuscript. The document editing processing section performs editing processing for the edit part identified by the edit part identification section, in units of electronic manuscripts.