Subject-based learning is usually applied on the lecture courses. Teachers teach related topics of a subject. However, the one-way teaching could lead to fossilization of learning. Problem-Based Learning (PBL) is a student-centered teaching method, which gives students the opportunity to examine and apply the information they learn. The purpose of this study is to evaluate the effectiveness of PBL applied on two lecture courses applying PBL in the Department of Product Design at Ming-Chuan Univerity. Action research as a qualitative research was adopted in the study. Results showed that PBL is especially appropriated to apply on students in the design field. However, PBL is not a panacea for everyone; active learners benefit more in PBL than others. Besides, action research well matches with education and benefits both teachers and students in the teaching and learning process because it meets the need of education and enables continuity in research with its cyclic process.