Colorectal cancer is the third most common malignancy and the third-leading cause of cancer-related deaths worldwide. In the last several years, recombinant DNA technology has made cancer gene therapy feasible in the clinic. In our studies, we used both exogenous and endogenous canstatin, a type IV collagen genetically distinct product. We detected the effects of canstatin on colorectal cancer cells HCT-15 and HCT-116. DAPI staining, FCM and migration analyse were used to detect the apoptotic cells, cell cycle and mobility. As shown in the results, the apoptotic cell numbers (p<0.05) and G1 arrest cell numbers (p<0.05) were higher than in the non-treatment case. The mobility of the cells was also decreased obviously (p<0.05). Simultaneously, combination effects of exogenous and endogenous canstatin were identified.