Abstract: Objective To investigate the expression of miR-124 in colon cancer and its effect on the biological behavior of colon cancer cells. Methods From May 2017 to December 2018,24 pairs of specimens of colon cancer and adjacent normal tissues were collected in our hospital.The expression of miR-124 was detected by RT-PCR.Human colon cancer cells SW480 were randomly divided into blank control group (untreated group),miR-124 mimic transfection group and miR-124 inhibitor transfection group.The cell proliferation ability was measured by MTT assay,and the cell invasion ability was detected by Transwell chamber assay. Results Compared with adjacent tissues,miR-124 was down-regulated in colon cancer tissues (P<0.05).Compared with the blank control group and miR-124 mimic transfection group,the cell proliferation activity and invasion ability of miR-124 inhibitor transfection group increased significantly (P<0.05,respectively). Conclusion miR-124 is low expressed in colon cancer and can inhibit the proliferation and migration of colon cancer cells.Abnormal expression of miR-124 may be one of the factors in the development and progression of colon cancer.