The business process model and service interaction model represent the behaviour model on business view and system view respectively. The automatic transformation from the business process model to the service interaction model can effectively narrow the gap between the business view and the system view. Thus, in this paper, a model transformation approach that can transform the business process model described by extended Petri net into service interaction model in system view is proposed. This approach by extending the UML sequence diagram meta model represents service interaction model, and by using model-driven development designs the transformation from extended Petri net to service interaction model. Especially, each situation of the behaviour transition linked to the different types of places in extended Petri net model are detailed analyzed. According with the these situation, the transformation rules from each situation to different types of message in the service interaction model are designed. In order to carry out the automatic executing of the formalization transformation, the transformation rules are described by the ATL model transformation language, and the ATL codes are implemented by Eclipse platform. Finally, the executing result of the model transformation plug is demonstrated by the Travel Agency system. The experimental results show that the approach in this paper can realize the automatic transformation from business process model to service interaction model, and improve the efficiency of software development.