I am Toshiki Hirao, a master course student at Nara Institute of Science and Technology (NAIST) in japan. I belong to Software Engineering Laboratory. My interests are Mining Software Repository (MSR), Empirical Software Engineering and Social Software Engineering. I research a Code Review Process of open source software development. In this research, I mine historical review data to find reviewer’s characteristics, behavior and so on. Recently, some researchers focus on a code review process in both proprietary and open source software systems. The goal of my research is to help developers to review more quickly and efficiently.