Many e-learning systems integrate advanced network technologies like web services, grid computing to achieve learning at anywhere anytime. However, most of them have not taken account of the process of study activities; learners are difficult to navigate the learning resources adaptive to their own pace. Though several recent researches provide workflow-based e-learning, formal definition and analysis of learning process, organization of distributed learning objects still have not be fully considered. This paper first introduced the formal definition method of workflow-based courses using fuzzy Petri nets, and then proposed a workflow based elearning architecture by utilizing workflow technology and learning object services. This architecture provides teachers tool for designing courses as composition of learning object services, and gives students the opportunities to achieve an orderly learning experience through adaptive navigating e-learning services step by step under the control of certain learning strategy. Some questions in application and future works are also discussed.