In　order　to　get　an　effective　mean　of　discriminating　services　at　a　level　of　granlarity,　based　on　the　semantic　description　of　Web　services＇　input　and　output,　the　issue　of　matching　semantic　Web　services　is　transformed　to　the　computation　of　semantic　distance　between　concepts　in　domain　ontology.　The　factors　of　path　lengh,　depth,　local　density　and　number　of　down　direction　are　taken　into　account　in　the　algorithm.　Finally,　it　improves　the　recall　and　precision.