Abstract: Objective To detect miR-16 expression in colorectal cancer and paired para-cancer normal tissues and explore effects of miR-16 on cell proliferation in HCT116 and LoVo cells. Methods Real time PCR was performed to detect miR-16 expression in paired colorectal cancer tissues and the surrounding nomal tissues. In cells transfected miR-16 inhibitors, non-target control and mimics, CCK-8 was used to test cell proliferation, fluorescence-activated cell sorter (FACS) to detect cell cycle, and western blot to examine protein expression of cyclinD1, CDK6 and GAPDH. Results (1) Results of real time PCR showed miR-16 was downregulated in colorectal cancer cells（P=0.047）. (2) Overexpression of miR-16 repressed cell proliferation; G₀/G₁ cell cycle was induced and the expression of cyclinD1 and CDK6 was reduced. Conclusion overexpression of miR-16 can inhibit cell proliferation in colorectal cancer cells.