Abstract: It is an important measure to promote the market-oriented reform of the IPO pricing system with the registration system as the core to improve the IPO pricing efficiency of China's stock market.Therefore,the IPO pricing efficiency of the STAR Market under the pilot registration-based system is particularly attractive.Based on whether IPO pricing can effectively reflect the company's intrinsic value,this paper uses a Stochastic Frontier Model to test the IPO pricing efficiency on the STAR Market,and on this basis,uses Mean Regression Model and Quantile Regression Model to test the impact of various influential factors on the pricing efficiency from the perspective of mean and conditional distribution.The study found that the average pricing efficiency of the sample companies was only 66.68%,and the IPO pricing was obviously overvalued,reaching 33.32%.The smaller the size of the company,the greater the degree of overestimation,and the reputation mechanism of underwriters doesn't play its due role;in addition,the estimation results of the Mean model and Quantile model show that the lead underwriters who have "only recommend but not guarantee" and moral hazard issues are still prominent,the sponsorship follow-up system does not have obvious restraint on leading underwriters.However,the role of STAR Market is very significant for companies in the range of high pricing efficiency.Therefore,the regulatory authorities should focus on the scientific and technological properties of IPO companies and the moral hazard on the lead underwriters.At the same time,the establishment of a balance of power,responsibility and interest and an effective incentive and restraint mechanism for market entities are still the core content of improving the system.

Keyword: STAR market; IPO pricing efficiency; stochastic frontier model; quantile regression model