Abstract: Objective To investigate the effect of gene GCRG213 siRNA transfection on the growth of MKN45 gastric cancer cells. Methods Two pairs of DNA sequences containing small hairpin structure of GCRG213 were designed and synthesized. A complement form was obtained by annealing and inserted into the RNAi expression vector IMG 800. Recombinant plasmid and vector were transfected separately into MKN45 cells. Expression of GCRG213 was detected by semi-quantitative RT-PCR and Western blot. Growth curves for MKN45 cells were plotted. FACS was used to detect cell cycle and two Annexin V FITC/PI parameters were used to detect the effects of gene GCRG213 siRNA transfection on cell apoptosis. Results The two pairs of DNA sequences containing small hairpin structure of GCRG213 were successfully cloned into the siRNA expression vector IMG 800. The recombinant plasmid and vector were transfected separately into MKN45 cells. Transfecting the siRNA vector into MKN45 cells significantly decreased the expression of GCRG213 at mRNA and protein level. The growth of MKN45 cells was slower than that of vector-transfected cells. The proportion of cells in Gz/M and/or S period was decreased and cell apoptosis was increased. Conclusion SiRNA transduction can inhibit the growth and proliferation of MKN4 cells,and promoted cell apoptosis.