In Japan, the concept and the practices of school evaluation have been developing into the external evaluation by stakeholders, such as parents and residents in the district, and the expert evaluation by professionals on education from the third parties. Now it is important to clarify problems and challenges to the study of educational administration in a new phase of school evaluation. We invited four speakers who presented the current progress of the study on school evaluation in Japan, the practices of school evaluation in UK, the third party evaluation systems in other countries and Japan, and the role of researchers in external and third party evaluation for schools. After four presentations we discussed the nature and the future of school evaluation. There were four points at issue described below. First, how and to what extent should the third parties of school evaluation be independent of state control and can they? In the discussion, a member was afraid that some people would misuse the system of third party evaluation because they mistook that this system should be independent only of schools. Second, we discussed the certificate for and the competence as school evaluator. Some members argued that our association could play an important role in these issues. Others said that it was not easy for us alone to undertake this task. We reached the conclusion that the collaboration among academic societies for the comprehensive school evaluation was important. Third, in this session there was a concern that external evaluation would prevent schools from using trial and error for creative educational practices; while another concern was that we could and had to use it in order to undertake bold and real educational reform. Fourth, the theory of educational administration has to reexamine the relationship between school self-management and external school evaluation.