Abstract: With the extensive application of database，data mining technology is expected to deal with great deal of data.The data mining system based on SOA is one of the solutions.The paper proposes a data mining services discovery method based on domain ontology.By introducing the domain knowledge and data mining ontology，the paper solves the problem of data mining service discovery.Firstly，the paper proposes the framework of data mining service discovery based on domain knowledge，and defines the ontology of data mining method and ontology of quality.Secondly，the paper presents the arithmetic of data mining service discovery according to domain knowledge and user’s requirement，which provides a successful solution for service selection of data mining.