Objective:To study the influence of PPARγ in mechanism that nimesulide regulates apoptosis and proliferation of human stomach cancer cells. Methods:MTT assay and flow cytometry(FCM) were used to determine the influence of GW9662(0.1,0.5,1.0,5.0 μmol/L),a PPARγ specific inhibitor,on proliferation and apoptosis of SGC-7901 cells,which would be treated with Nimesulide in half an hour. Results:GW9662 can inhibited apoptosis of human stomach cancer cells caused by Nimesulide in a dose-dependent manner in a relative valid range and significantly decresed the proportion of cells in the G0/G1 phase,increased the proportion of cells in the S phase. Conclusion:GW9662 can partly inhibit the effects caused by nimesulide that regulates apoptosis and proliferation of human stomach cancer cells,which supposed PPARγ pathway is probably an important way for the effects of NSAIDs.