Web Services following distributed object computing technology like DCOM, CORBA provides remote procedure call mechanism based on XML-based open standard such as SOAP, WSDL, UDDI, and it is spotlighted as means of integration and collaboration at e-business. Especially, UDDI is the Web Services Registry enabling to register and search Web Services, that takes charge of providing infrastructure for Web Services. However, the existing UDDI has a few problems that searching process is very simple and it cannot provide information of Web Services quality and quality-based retrieval. Therefore, this study suggest improved UDDI model that evaluates the Web Services quality and use this information for searching.