Abstract: The post-issue operating performance over 3 years after their IPOs of 40 companies in Liaoning Province, which were listed as the A-share firms on stock market from January 1996 to July 2002, is discussed, and the main influencing factors on their business performance are analyzed. Using the Fama-French tri-factor model, the long-term excess profits of those companies over 3 years after their IPOs are calculated to examine their long-term performance. Furthermore, the multi-idividual-sampled Kruskal-Wallis verification, dual-individual-sampled Mann-Whitney U verification and multi-variable regression analysis are used to find out the main influencing factors on the long-term performance. A conclusion is drawn that the long-term performance of the 40 A-share listed companies went to weak on stock market on the whole, and that their performance is in negative correlation with issuing time, volume and price.