<FONT face=Verdana>The paper proposes an OWL-S based semantic web service matchmaking system mecha nism

which imports semantic elements into UDDI

and preserves semantic information in UDDI storage.The system employs a semantic service matchmaking algorithm to improve precision and recall of service matching

and uses a data mapping mechan ism to ensure the compatibility with present web service discovery standards

UDDI

and the transparency of UDDI APIs.The paper designs an ontology concept indexi ng mechanism for the system to improve the efficiency of service discovery.Moreover

in the processes of building and maintaining the indices

or alternatively

matching services

the system uses a similar concept searching algorithm to further enhance the efficiency of ontology concept searching and service matchmaking.