The purpose of this study was to investigate the effects of teacher evaluation on professional development programs implemented in elementary schools in Taipei. The participants of this study were six purposefully chosen elementary schools which had participated in the teacher evaluation projects launched by the Ministry of Education from 2006 to 2007. To achieve the above purpose, this study adopted qualitative approach and the data had been collected by observing, interviewing and document analyzing. The results of this study were as follows: Regarding the effect on individual teachers: On the bright side, teachers were motivated to reflect on their teaching, which led to the advancing of their professional knowledge, the increasing of their teaching efficiency, and the promoting of their sense of professionalism. On the other hand, some teachers and one of the six schools quitted attributed to the burden of extra workload. Regarding the effect on school organization: On the positive side, these programs had served as a communication platform where teachers were able to share their teaching thoughts and views. As a result, teachers' negative views toward the evaluation such as fears were diminished. Nevertheless, doubts about the worthiness of the programs still existed owing to other factors. Peer pressures were generated between groups of teachers who did and did not join the evaluation. Regulations might be required to enforce teachers’ immediate participation. Regarding the effect on the environment: Although parents were affirmative toward teacher evaluation programs, what concerned them most was the issue of unqualified teachers.