Objective:To analyze the role of Rho GTPase activating protein (RhoGAP) domain of frequently deleted in liver(DLC-1) gene in suppression of proliferation and invasion in colon cancer HT29 cells. Methods:Recombinant pcDNA3.1 vector containing the DLC-1 gene and RhoGAP domain deleted ΔDLC1 subclone was constructed and transfected into HT29 cell line. The cell growth was measured by MTT and colony formation assay. The ability of cell migration of HT29 cells was examined by using Transwell migration assays. Furthermore,cell cycle was evaluated by flow cytometry. Results:After transfected successfully,pcDNA3.1-DLC1-HT29 cells showed a remarkable suppression of proliferation and invasion,as well as G1 sphase arrested and apoptosis induced,compared with wild or mock-vector HT29 cells. However,pcDNA3.1-ΔDLC1 subclone transfection had no effect on cell proliferation,invasion and cell cycle distribution. Conclusion:DLC-1 gene inhibits proliferation and invasion of colon cancer HT29 cells via its RhoGAP domain.