As an important phase in software development, domain modeling can be used to construct reusable domain assets based on common domain requirements. In service- oriented software development, domain modeling is essential to satisfy users’ personalized requirements in a short time and at a low cost. We have proposed a method named O-RGPS for service-oriented domain modeling. In O-RGPS, goal models and process models are two kinds of important domain models that have tight relations. However, process modeling is not an easy task in domain modeling since the process models are usually very complicated, and some properties and relations have the risk of being missed. Towards this problem, this paper proposes an automatic process model generation approach by transforming the goal model. Algorithms for generating process models are designed by sufficiently analyzing decomposition and dependence relations in the goal model and transforming these relations into the process model. Furthermore, the method has been realized in a domain modeling prototype, which aims at helping domain experts in domain modeling. The experiments show that this method can help to reduce modeling time and improve the quality of models during creating process models.