Using 1,559 IPO firm data from the GSMAR database for 13 years from 2003 to 2015, we investigate the honeymoon effect of IPO and the impact of stock lock on long-term market performance of IPO firms with following results. Through this study, we found that firms with longer honeymoon periods have a better long-term market performance of IPO firms. This will lead firms to maintain their honeymoon period in various ways such as lock-up period. On contrary, our study found that higher lock-up stock period and Higher lock-up stock ratio will lead underperformance of IPO firms. The impact of lock-up stock on the stock market is complex and variable. Therefore, firms should consider short-term and long-term performance when setting stock lock periods. The disadvantage of this paper is that it only considered the honeymoon period, not the honeymoon return. This section will be supplemented in future studies.