Abstract: In order to improve the level of flexibility, recall and precision of Web services matchmaking, a domain ontologies-based complex approach for services matching is proposed. Firstly, expressions of Web service and service request using domain ontologies as description language are outlined. Then a three-level matching model is proposed to discover web services, which caters to high flexibility. Meanwhile relative similarity functions are introduced to rank web services in services matching, which comprehensively present factors impacting the level of recall and precision. Finally, the matchmaking approach is proved to be feasible and effective by some comparative experiments.