Abstract: Objective The aim of the research was to investigate the influence of S100A6 on the growth,proliferation,apopatosis,infiltration and cell cycle of the gastric cancer line MKN45. Methods As a critical member of S100 gene family,the cDNA of S100A6 was subcloned into a constitutive vector pcDNA3.1 followed by transfection in MKN45 by using liposome.Then stable expression clones were screened and appraised.The stable cell line MKN-S100A6 as well as two control groups were investigated.The cell apoptosis and cell cycles were determined by using the flow cytometry.The growth and proliferation were analyzed with cell growth curves and colony formation assay respectively.The ability of infiltration was also tested using cancer cell migration assay. Results MKN-S100A6 cells grew faster than MKN45 and MKN-PC.The cell counts of MKN-S100A6 in five of seven days were more than that of others significantly (P<0.05).There was no difference between two control group.Cell cycle analysis showed that MKN-S100A6 group proliferated faster,proportions of cells at G2-M phase were higher and at S phase were lower significantly(P<0.05) than that of two control group. Results of colony formation assay showed that the colony formation rate of MKN-S100A6 was higher than that of control groups (P<0.05).The results of cell migration assay suggested that the cell migration rate of MKN-S100A6 was higher significantly that that of control groups (P<0.05). Conclusion Although it can have little influence on the apoptosis,S100A6 can promote cell growth and proliferation.It can increase the proportion of cells in division stage,thus promoting the cell division.It can promote infiltration and metastasis of gastric cancer cells.So S100A6 gene can help tumor cell maintain malignant phenotype.