This study investigated the mechanism between Chinese undergraduates' quality of effort in college activities and learning gains, using the Chinese College Student Experiences Questionnaire (CCSEQ). 2,990 undergraduates were recruited at a case Chinese university. Gender, grade, and type of high school differences were found in Chinese undergraduates' quality of effort in college activities and learning gains. Compared with data from American Norms, Chinese undergraduates have less interaction with teachers, lower classroom participation, and lower intellectual skills gains. Quality of effort in college activities contributed more to learning gains than demographics, with different influences based on the types of college activities. This research verifies the applicability of the CSEQ in the Chinese context and reveals the characteristics of the learning experiences of Chinese undergraduates and the underlying reasons. Recommendations for programme designers, university faculty, and undergraduates themselves were suggested.