Automatic service identification and quality evaluation is one of key characteristics for a Service-Oriented Computing, being receiving a lot of attention from researchers in recent years. However, most researchers focus on identifying and evaluating application services and do not present methods for automatically identifying and evaluating business services from business processes. In general, the manual business service identification process by a human expert is a highly expensive and ambiguous task and may result in the service design with bad quality because of errors and misconception. We propose an automatic business service identification and quality evaluation method using Enterprise Architecture as a machine understandable knowledge-base. We verify the effectiveness of the proposed method through a case study on Department of Defense Enterprise Architecture.