Objective To explore the teaching effects of an online case-based learning (CBL) system for prosthodontics. Methods 25 graduate students in clinical practice at the Department of Prosthodontics, Peking University School of Stomatology during 2019 participated in an online CBL system for prosthodontics for one week. All candidates had received learning training using traditional case-based learning system before the online training. After the study, a questionnaire survey including Likert scale was conducted for graduate students. The convenience of using, the ability to promote clinical thinking, and the ability to increase clinical experience were evaluated between traditional CBL system and the online CBL system for prosthodontics using the paired t test. The questionnaire was conducted anonymously. Results Compared with traditional CBL system, the online CBL system for prosthodontics has better convenience[(4.20±0.82)vs(3.80±0.41),P=0.01] There is no significant difference in improvement thinking ability [(4.06±0.89)vs(3.84±0.37),P=0.03]. It can better improve clinical ability of postgraduates [(4.00±0.82)vs(3.76±0.44),P=0.13]. More than 72.0% (18/25) of candidates accepted and were willing to continue to use the online CBL system, and 40.0% (10/25) of candidates are willing to use the online CBL system by using sporadic time. Conclusions The online CBL system for prosthodontics is a convenient way for learning with good practicality, which is accepted by most candidates.