Taking IPO companies from July 2009 to December 2017 as samples， this paper investigates the impact of media rent-seeking and investor sentiment on IPO underpricing. The study finds that high investor sentiment will encourage IPO underpricing； media rent-seeking will promote the IPO underpricing by intensifying investor sentiment； this exacerbation of media rent-seeking is more powerful when investors are depressed about the overall capital market. The possible reason is that media rent-seeking will make over-confident investors overestimate the accuracy of their own information. What’s worse， media rent-seeking will distort historical information and make investors with rear-view mirror bias make more improper judgments， which will lead to further overvaluation of new stock prices. After using the PSM method to weaken the endogenous problem and replace the media rent-seeking index to test the robustness， the research conclusions obtained are still valid.