This degree project is mainly discussing about a web service classification approach based on suffix tree algorithm. Nowadays, Web Services are made up of WSDL web Service, RESTful web Service and many traditional component Services on Internet. The cost of manual classification cannot satisfy the increasing web services, so this paper proposes an approach to automatically classify web service because of this approach only relies on the textual description of service. Though semantic similarity calculation, we achieve web service classification automatically. Experimental evaluation results show that this approach has an acceptable and stable efficiency on precision and recall.