The main purpose of this study was to develop a program outcomes assessment tool using reflection journal. Reflection journal has recently come to gain more attention from school as an alternative assessment tool. Although numerous studies reconfirmed the educational importance and value of reflection journal as an assessment tool, research on the assessment tool of the engineering accreditation, based on education view is scarce. After literature reviews about the case studies on the program outcomes assessment, this study, to analyse the current assessment tools, and then, examined the educational implications of reflection journal as a program outcomes assessment tool. This study suggested the assessment tool using reflection journal for PO6 (teamwork) and PO11 (engineering ethics), one of the most important assessment items in engineering accreditation. In this study, we used the performance criteria, assessment criteria, rubric, and closed the loop to measure the teamwork and engineering ethics. The result of this study is significant in terms of guiding the future evaluation system development for program outcomes.