In this paper, we undertake a duration analysis on the time intervals between firms's IPOS and their first SEOS in china. It suggests that the firms with larger amount of outstanding state-owned shares are more likely to make SEOS immediately after IPOS. And the result is robust after controlling for the firm characteristics. Further research indicates that the firms with larger amount of outstanding state-owned shares are are less likely to qualify for the ROA requirements. This gives strong evidence to the conjecture that government policy has done in favor of state-owned enterprises in the approvals of SEOS.