Objective To study the effects of isoproterenol (ISO) on apoptosis in human gastric cancer cells(NKM-45 cells).Methods NKM -45 cells were cultured with the medium contained various concentrations (15,30,60 μmol/L) of isoproterenol for 24 hours. Apoptosis rates were detected with TUNEL. The expressions of Bcl2 and P 53 genes were detected by immunohistochemistry. Results ISO markedly increased apoptosis rate in NKM-45 cells(P0.01), and the apoptosis rate was incresed with the advances of the concentration of ISO (P0.01). The expression of Bcl-2 and P 53 was decreased with the advances of the concentration of ISO (P 0.01). Apoptosis rate in NKM-45 cells was closely related to the expressions of Bcl-2 and P 53 (r = -0.93,P0.01 and r = -0.99,P0.01). Conclusion ISO can stimulates apoptosis in NKM-45 cells. The apoptosis of NKM -45 cells is association with an decrease in Bcl-2 and P 53 expression.