Abstract:
The purposes of this research were to develop, and to study the results of using the developed teacher professional development program for communicative language teaching using a community of practice approach. The research process proceeded with the synthetic of a community of practice approach. The participants were the teachers who had taught English in the secondary school at Bantan district, Chaiyaphum province who, were willing to participate to use the teacher professional development program. The instruments of this research were; the teacher professional development program, the recording of focus group interviews, and the evaluation form of communicative language teachings competency. The qualitative data analysis was analyzed by content analysis and the quantitative data analysis was analyzed by mean, standard, and development score. The results of this research: were as follows; 1. The participants had changes on Communicative Language Teaching Belief after using the program. There were 2 issues that were unchanged, due to the participants had correct belief and conform to communicative language teaching approach which followed the communicative language teaching of the basic for communicating in the real context and the role of the teacher for communicative language teaching. 2. Participants had a good level of communicative language teaching competencies after using the teacher professional development program (X = 4.70, SD = 0.49). The development score of the evaluation of communicative language teaching competencies was higher than before using the program followed by an increase of relative gain score at a high level (58.47).