Enterprise Architecture (EA) has become an important means to acquire and maintain knowledge about the structure and behavior of the enterprises and to develop the required IT systems. Two main goals in architecture - high flexibility and low complexity- are addressed in a new architectural style called Service Oriented Architecture (SOA). In this paper, we discuss approaches to have SOA models in the enterprise architecture framework. Based on an analysis of these approaches, we propose an extension to the Zachman Framework called SOEAF, in order to provide the framework with the capability to include serviceoriented artifacts representing services aspect of the enterprise. Then we will propose a Model Driven Approach (MDA) to Service Oriented Enterprise Architecture (SOEA), in which, MDA concepts, standards and tools help us achieve a semi-automated service-based analysis and design of the enterprise IT systems. The proposed approach can be very beneficial for increasing efficiency ...