In order to research the effect of stretch on the cells, the four-point supporting bending system is applied to stretch the SMMC-7721 hepatocellular carcinoma cells. Then, the proliferation of the cells was determined by FCM, and the morphology is measured by computer-image-processing, the result show that (1) The percent of G 2-M phase of SMMC-7721 is reduced after 24 h stretch (8.63% in 24 h stretched group and 15.92% in control). (2) The project area of SMMC-7721 is reduced after 72 h stretch. (3) The proliferation of SMMC-7721 is inhibited by stretch (the division index of SMMC-7721 in 24 h stretched group is 0.46, in control group is 0.55).