This paper describes a consideration about organization method of groups for PBL (Problem Based Learning) that using robots as teaching materials. Author tried an educational program that combined the “Jigsaw method” with the “PBL” in FY2013 to a class of 5th grade students of a KOSEN (College of technology). In PBL program in Ibaraki KOSEN, there were some problem caused by a difference in skill level between “Robot club students” and “Non-robot club students”. To solve these problems, author combined the Jigsaw method with the ordinary PBL and gave some small lectures based on Jigsaw method to “Non-robot club students”. As a result, 4 groups completely succeed in assigned problem about a line trace robot. This paper also discribes about a correlation between the performance of the robot made by students and marks for lectures of the student. These results suggest about the most suitable organization method for PBL.