Cell division is one of the key roles in cell development, cell differentiation, embryogenesis and recovery of tissues. As a frequent stimulus, stress (or strain) plays an important role in the differentiation of the cells, morphology generation and function development of tissues. However, this stimulus was not studied enough. A uniaxial static stretch device was used to investigate the influence of a uniaxial stress on stress fibers and spindle orientation of cultured Murine osteoblast line (MC3T3). The cells were seeded for 24 h on a thin rectangular silicon membrane in the uniaxial device before the static uniaxial stretch was applied to them. Five groups of the cells experiencing 4% strain for 48 h, 8% strain for 6 h, 8% strain for 12 h, 8% strain for 24 h, and 8% strain for 48 h were observed. After the stretching, the cells were incubated in fluorescent rhodamine-conjugated phalloidin and DAPI staining solution for 30 min. The stress fiber alignment and the cell division directions of the cells were recorded by CCD camera with an inverted fluorescent microscope (Olympus 71X) equipped with a green filter (554 nm). In fact, the cells that were growing individually were counted because the interaction between cells may influence the cell alignment and the mitosis orientation. These cells were divided into three groups, 0°～30°, 30°～60°, 60°～90°. The cells in each group were counted, then the distribution of the cell division directions were plotted in the circular graphs. It was showed that the morphology of the cells was regulated by 4% and 8% static uniaxial strain. Within 48 h, the uniaxial stress induced the stress fibers' alignment parallel to the stress direction while a random distribution of the long axial of the cells was seen in the control group. 49%, 43%, 54%, 54%, 62% of the cells under the five experimental conditions fall into the group Ⅰ(0°～30°) according to the angles between the stretch directions and the stress fibers alignments. And, there are 50%, 48%, 56%, 53%, and 62% of the cells under the five stretch conditions in group Ⅰ(0°～30°) according to the angles between the stretch and the cell division directions. Further statistic analysis indicates that the stress fibers' orientation and mitosis orientation show high relativity. The relativity was very high even 48 h after the stretch stimulus. These results suggest that the mechanical environment of the cells may play a role in the cell division orientation. The effect of cycle stress on cells mitosis orientation is worth further study.