The study investigates the effect of project-based learning on the intrinsic motivation of private college students learning English in China. Motivation is instrumental to students’ learning process, private college students in China are less academically motivated than their counterparts in public institutions. Project-based learning is an effective instructional technique that empowers students to be the center of learning. In this action research, 21 students learning English in a private Chinese college were administered with the Intrinsic Motivation Inventory to examine the difference of their intrinsic motivation level before and after a project. The result of the study shows significant difference existing in interest, autonomy, competence and pressure students perceived before and after the project, which supports project-based learning has a positive impact on students’ intrinsic motivation for learning. Based on this result, it is highly suggested that more considerations should be given to incorporate PBL in course design to enhance intrinsic motivation of private college students in China.