Abstract: Objective : To observe the influence of RPS12-specific RNA interference on the apoptosis of BGC823gastric cancer cells and to determine a possible mechanism. Methods : The RPS12-specific shRNA expres-sion vector was designed, constructed and transfected into gastric cancer cells using lipofectamine 2000.Scramble-shRNA was used as the control. The expression of RPS12 and apoptosis-associated genes Bcl-2and Bax was examined by RT-PCR. Apoptosis of gastric cancer cells was detected by flow cytometry. Results :RT-PCR showed that RPS12 mRNA expression was markedly downregulated on day 3, 5, and 7 after trans-fection of the RPS12-shRNA expression vector, especially on day 5. The expression of Bcl-2 mRNA was sig-nificantly downregulated on day 5 and 7 after transfection of the RPS12-shRNA vector. No changes werefound in Bax mRNA expression. On day 7 after transfection, the apoptosis rate of the transfected cells(17.84%) was higher than that of the control cells (1.89%). Conclusion : Suppression of the RPS12 gene withRNAi can increase apoptosis of gastric cancer cells, possibly by downregulating the upstream expression ofBcl-2.