Objective: To investigate the effects and mechanisms of miR-126-5p on proliferation, migration, invasion and apoptosis of colon cancer SW480 cells. Methods: Cells were transferred with miR-126 mimic and pcDNA Notch2 (pc-Notch2) respectively or simultaneously. Real-time fluorescence quantitative PCR was performed to detect the expression of miR-126 and Notch2. The relationship of miR-126-5p and Notch2 was determined by luciferase reporter assay. The CCK-8 assay, wound healing assay, Transwell and flow cytometry were performed to examine cell proliferation, migration, invasion and apoptosis, respectively. The protein levels of Notch2, proliferating cell nuclear antigen (PCNA), cleaved Caspase-3, metalloproteinase-2 (MMP-2) and MMP-9 were measured by Western blotting. Results: miR-126 mimic significantly increased expression level of miR-126-5p but reduced the expression of Notch2 in SW480 cells (all P<0.01); in the meanwhile, a binding site with miR-126-5p was confirmed on Notch2. Up-regulating the expression of miR-126-5p inhibited cell proliferation and the expression of PCNA (P<0.01), increased the cell apoptosis rate and protein level of cleaved Caspase-3 notably (all P<0.01). Pc-Notch2 obviously alleviated the effects of miR-126 mimic on cell proliferation and apoptosis (all P<0.01). Furthermore, miR-126 mimic significantly decreased the wound healing rate and invasive cell numbers (all P<0.01), and down-regulated the expressions of MMP-2 and MMP-9 (P<0.01); pc-Notch2 alleviated the effects of miR-126 mimic on cell migration, invasion and the expressions of MMP-2 and MMP-9 (all P<0.01). Conclusion: miR-126-5p can attenuate proliferation, migration and invasive ability of colon SW480 cells via inhibiting the expression of Notch2.