The resource query mechanism is mostly based on keywords in most P2P systems at present. It limits resources sharing to some extent. Along with the emergency of semantic web technology, sharing resource at the semantic level in P2P system becomes a new hot topic. Based on ontology technology, the integrated model and the heterogeneous resources integration approach in a P2P system are studied in this paper. The mapping rules from multi-resources to ontology and the semantic mapping rules between different kinds of ontologies are defined. A general model for sharing resources in P2P systems based on semantic technologies is designed. The model structures of system and peer are described. A method for measuring the semantic similarity between peers is designed and query processing is illustrated.