The internal supervision of colleges is important and essential for improving the quality of education to achieve the goals. It can be operated by personnel who have a close relationship with teachers, know and understand current situations, requirements, strengths, and limitations of
the college. Thus, there should be an internal supervision model for all college administrators and personnel to use as an operational guideline to improve the quality of teaching and learning. The purposes of this research were: 1) to study the current situation of internal supervision of polytechnic colleges in Eastern Thailand; 2) to develop the internal supervision model of polytechnic colleges in Eastern Thailand; 3) to evaluate the internal supervision model of polytechnic colleges in Eastern Thailand. This research consists of 4 steps. Step 1: Study the theory, papers and related research in accordance with the guidelines. Step 2: Examine the current situation of internal supervision of polytechnic colleges in Eastern Thailand. Step 3: Draft the internal supervision model of polytechnic colleges in Eastern Thailand. Step 4: Examine and evaluate the draft of the internal supervision model of polytechnic colleges in Eastern Thailand. The research population consisted of 2 groups. The first group were 98 polytechnic college teachers in academic year 2017 who participated in step 2. The second group were 14 and 5 people who participated in step 3 and 4 respectively. The research tools were: I) a five-rating scale questionnaire with a discrimination of between 0.62 and 0.90 and a reliability of 0.98, 2) focus group discussion summaries, and 3) model quality assessment. The mean and standard deviation are statistical tool using for data analysis.