Based on the hypothesis that the instructional style in Project-Based Learning (PBL) is related to in-house On-the-Job Training (OJT), the scores of the Diamond inventory of Learning Leader (DLL), an OJT test, were investigated before and after taking charge of PBL classes. Except for one instructor, the scores of DLL for all instructors increased by about 0.6～25.3 compared to their scores before taking charge of the PBL classes. Instructors who were in charge of PBL classes for the first time indicated that about 85% of the DLL questions were related to the instructional style in PBL, and instructors who were in charge of PBL classes more than twice indicated that about 68% of the DLL questions were related to the instructional style in PBL.
