[Abstract] Objective: To investigate the effects of over-expressing VASH1 on the malignant biological behaviors of human colorectal cancer cells. Methods: Lentivirus was packaged and transfected into human colorectal cancer cells SW680 and SW620 to construct an over-expressed VASH1 cell line, the untransfected cells were used as control. qPCR experiment and WB experiment were used to detect the over-expression effect of VASH1. The effects of VASH1 over-expressed on microangiogenesis, proliferation, colony formation and migration of colorectal cancer cells were detected respectively by tubule formation, CCK-8 assay, soft agar assay, Transwell assay and Wound healing assay in vitro. In addition, tumor growth and lung metastasis were detected in NOD-SCID mice subcutaneously injected with VASH1-overexpressing SW620 cells. Results: Successfully constructed SW480 and SW620 cells over-expressing VASH1. Compared with the control group, the abilities of microangiogenesis, proliferation, colony forming and migration were significantly reduced in colorectal cancer cells over-expressing VASH1 (P<0.05) in vitro. The abilities of subcutaneous tumor growth and lung metastasis of colorectal cancer cells over-expressing VASH1 were also significantly reduced (P<0.05) in vivo. Conclusion: Over-expression of VASH1 can suppress the malignant biological behaviors of human colorectal cancer cells.