Ontology provides sharing knowledge among different data sources which will help to clarify the semantics of information. OWL is being promoted as a standard for web ontology language, thus in the future a considerable number of ontologies will be created based on OWL. Therefore automatically detecting semantic conflicts based on OWL will greatly expedite the step to achieve semantic interoperability, and will greatly reduce the manual work to detect semantic conflicts. In this paper, we summarize seven cases based on OWL in which semantic conflicts are easily to be encountered, and for each case, we give a rule to resolve the conflict. Via a series of examples, we show how this method works. Based on the seven cases, we propose a semantic conflicts detection and resolution algorithm. This aims at providing a semiautomatic method for semantic uniform data interoperability and integration.