This paper brings forward an ontology description structure called FLoDS (Four-layer ontology Description Structure) which contains object layer, attribute layer, definition layer, and relation layer. Then an ontology description language called FLoDL (Four-layer ontology Description Language) based on FLoDS is also presented. We use knowledge description methods of frame theory in semantic level and XML specifications in grammar level in FLoDL. Based on FLoDS and FLoDL, the architecture of semantic cooperative editing system is proposed. It has the ability of keeping semantic consistency of the shared document. It also can provide the semantic personalized services for different users and maintain the users? semantic intentions. The algorithm of the server side of the architecture is also given.