In the paper, we analyze the shortages of service-oriented analysis and design (SOAD) methodologies, and propose a SOAD method based on use case approach. Therefore, a service model is designed to facilitate service identification from use case script. Moreover, a process is provided as a guideline to aid an analyst to accomplish highquality service identification with the method. By analyzing basic characteristics and an illustration of the method, we can conclude that the method has several strong points compared to other methods which are based on business process modeling and enterprise architecture.