Manual test case generation is time consuming. Manual test cases lose their usability after some time because services are dynamically published, bound, invoked and integrated. This makes automatic test case generation more important. Automatic Test Case Generation of SOA Based Services provide fundamental concept of SOA testing and investigated various SOA testing perspectives and SOA testing challenges. Our discussion include some existing testing techniques like-Data Perturbation Technique, Web Service Group testing (WSGT)Technique, Tag Based Testing Technique and some model based approaches to test SOA based services. Further, We explain our novel testing model with the help of our test case generation algorithm and test case selection algorithm.