Objective:To investigate the effects of 5-Aza-2’-deoxycytidine(5-Aza-CdR) a methylation inhibitor on the growth of human renal carcinoma cell line OS-RC-2,and the DNA CpG island demethylation of γ-catenin gene so as to provide insights into origin of renal carcinoma and the possibility of its application in clinical treatment. Methods:MTT method and flow cytometry were used to detect the growth and appoptosis of OS-RC-2 after 5-Aza-CdR treatment respctirely. The western blot was used to detevt γ-catenin protein levels in the cell line before and after treatment with 5-Aza-CdR.The methylation and demethylation status of γ-catenin gene were volume detected by methylation special PCR(MSP). Results:The morphological pattern changes were observed invert-microscope. OS-RC-2 cells treated with 5-Aza-CdR displayed a slowed growth in comparision with the control cells. The apoptotic rate was also increased after 5-Aza-CdR treatment. Western blot indicated that expression of γ-catenin protein was recovered by 5-Aza-CdR treatment. The high methylation status of γ-catenin gene promoter region was reversed with 10-5 mol/L 5-Aza-CdR treated for 72 h. Conclusion:5-Aza-CdR effectively causes the demethylation of γ-catenin gene CpG-rich promoter regions, and recover the γ-catenin protein expression, subequenely induce the appoptosis of OS-RC-2 cells.