Abstract: Objective To investigate the effect of traumatic occlusion on the development of condylar.Methods Twenty-seven male SD rats were randomly divided into three groups, the traumatic side, the opposite side and blank control group. The rats of experiment group were perpormed to bond 1 mm steel-wire on left upper molar, the blank group were breeding normally. The condylar was dissected when the rats were 1, 3, 5 weeks after experiment. The histology section was used to observe the morphology of condylar. The immunohistochemical staining was used to examine the PCNA positive cell, TUNEL was chosen to detect the apoptotic cell.Results The histology section showed there was no significant difference between the three groups, the immunochemical stain and TUNEL showed there was no significant difference in the proliferated and apoptotic cells with 1, 5 week after experiment; the proliferated cell number decreased while the apoptotic cell increased on the traumatic side with 3 weeks after experiment, there was significant difference between three groups. Conclusion One side traumatic occlusion has no significant effect on condylar morphology, however has some influence on cell growth, it suggests that traumatic occlusion to some extent has no obvious effect on condylar growth.