OBJECTIVE: To detect miR-200a expression in human colorectal carcinnoma (CRC) cell lines and explore the role of miR-200a in regulating the biological behavior of CRC cells. METHODS: Real-time quantitative RT-PCR (qRT-PCR) was used to detect miR-200a expression levels in 6 CRC cell lines (HCT116, HT29, LS174T, SW480, SW620 and LoVo). miR-200a mimics were transiently transfected into LoVo, and the changes in cell proliferation, apoptosis, migration, and cell-cell adhesion were assessed using CCK-8 assay, TUNEL assay, transwell migration assay, and homogenous adhesion experiment, respectively. RESULTS: The expression of miR-200a was down-regulated in the 6 CRC cell lines, among which the highly metastatic LoVo cell line showed the lowest expression and the tumorigenic but non-metastatic CRC cell line HCT116 had the highest expression. Overexpression of miR-200a depressed cell proliferation and migration but promoted cell apoptosis and cell-cell adhesion in LoVo cells. CONCLUSION: miR-200a plays a role in regulating the invasiveness and metastasis of CRC, and overexpression of miR-200a causes a significant reduction of cell proliferation and migration and promotes apoptosis and cell-cell adhesion in LoVo cells.