This study aims to measure the returns on IPO stocks in the Chinese IPO market for A-shares by decomposing them into initial return, issuance return, aftermarket return, and initial realizable return, and to identify the factors affecting each sub-return. The main research findings are as follows. First, while the degree of underpricing of Chinese IPO stocks has gradually decreased over time, it remains at a very high level compared to developed markets. Second, examination of the cumulative abnormal returns of IPO stocks by period confirmed that most of the high abnormal returns of Chinese IPO stocks are attributable to the initial return. Third, the majority of the initial return was composed of the issuance return, and the proportion accounted for by the aftermarket return was found to be very small. Fourth, in the case of issuance returns, general determinants of IPO returns such as AGE, GAP, ZQL, and reputation rank were found to have significant effects, but in the case of aftermarket returns, the effects of other factors were not significant except for turnover. Fifth, when investing in Chinese IPO stocks, if one fails to be allocated shares in the public offering, the probability of achieving positive (+) returns through trading in the secondary market does not reach 50%; however, investing based on turnover, which significantly affects aftermarket returns, can reduce the possibility of losses. The results of this study indicate that Chinese IPOs are severely underpriced, so investors who are allocated shares in the public offering can realize high returns; however, this undervaluation is mostly resolved simultaneously with listing. Therefore, if one fails to be allocated shares in the public offering, opportunities to earn returns through IPO investment in the secondary market are significantly reduced. Nevertheless, if one intends to invest in IPO stocks in the secondary market, turnover should be considered as the most important variable.