Objective To investigate the effect of AP-2α on the chemoresistance to oxaliplatin of colorectal carcinoma cell and its related mechanism.Methods Plasmid of GV102-AP-2α-RNAi (experimental group) and control plasmid GV102-NC (negative control group) were transfected into HCT-116 using Lipofectamine 2000 respectively.The AP-2α expression levels of mRNA and protein of experimental group,control group and HCT-116 blank group were detected by qRT-PCR and Western blot.Cell proliferation assay was performed using the CCK-8 and the apoptosis assays were preformed with Annexin V-PE Apoptosis Kit.Results The AP-2α expression levels of mRNA and protein both decreased after transfection of AP-2α-RNAi plasmid,moreover,the effect produced by subsequence 1 was the most significant.After treatment by oxaliplatin,AP-2α protein levels increased with time while mRNA did not change significantly.Western blot results suggested that the level of AP-2α protein in experimental group which was maintained in oxaliplatin was lower than the negative control group.CCK-8 results suggested that cell proliferation ability was significantly higher for the experimental group maintained in oxaliplatin [(88±3) ％] than the negative control group maintained in oxaliplatin [(57±3) ％] and the blank group maintained in oxaliplatin [(73t4) ％].Flow cytometry showed that the apoptosis rate of the experimental group maintained in oxaliplatin [(15.07±1.20) ％] was lower than the control group maintained in oxaliplatin [(24.93±0.90) ％] and the blank group maintained in oxaliplatin [(23.71±1.32) ％].Conclusion AP-2α may be related to the sensitivity of colon cancer cells to oxaliplatin.