Abstract：Purpose To investigate the potential role of H2-calponin in the proliferation of colon cancer. Methods Expression of H2-calponin was investigated in colon cancer, adjacent, normal colonic tissues and 5 colon cancer cell lines by Western Blot. Downexpression of H2-calponin was obtained by transfection with human H2-calponin-specific small interference RNA (H2-calponin-siRNA) vector in colon cancer cells SW480. Using this cell line, cell proliferation was detected by MTT assay and cell cycle was analyzed by flow cytometry. Results Expression of H2-calponin was found significantly lower in colon cancer tissues compared to that in adjacent and normal tissues. Downregulation of H2- calponin significantly increased cell growth in MTT assay. Cell cycle analysis further revealed that H2- calponin induced cell cycle arrest at G1/S phase. Conclusion H2-calponin could inhibit the proliferation of colon cancer.