There are no summative evaluations for compulsory and basic education in Taiwan. This research discusses and analyzes present teacher evaluation implementation. The implementation of policy nowadays means "Teacher evaluation for professional development". Teacher evaluation for professional development is a voluntary growing project of the Ministry of Education. The objective of this research is to understand the professional development of teachers and school leaders as a microscopic phenomenon, and discuss the interaction between strategies for school principals' leadership and teachers' professional development. This research attempts to understand the correlation between school leadership and teacher evaluaction for professional development. The case study used the qualitative narrative inquiry method to gather information in the form of documents, records, interviews and observations. This research deals with both teacher evaluation policies and school case experiences in Taiwan. Finally, the study concludes with recommendations on enhancing the school administrative units. It also provides some suggestions for teacher evaluation programs in the future.