Abstract: Objective：To investigate effects of osteoporosis on osteointegration of implants in tibias of rats. Methods：Twenty old female Wistar rats were randomly divided into two groups: Sham（control group）and OVX （model group）. The serum alkaline phosphatase (ALP) activity was measured before and 3 months after operation. Shin bone mineral density and HE staining were examined 3 months after operation. One implant was inserted in a tibia of each rat in Sham and OVX groups. Four and eight weeks after implantation, tibias with implants were taken pictures of by X-ray. The osteointegration of bones and implants in each group were observed by histological slices and SEM scanning. Results：Three months later, tibias showed decreased bone density and trabecularism porosity enlargement in OVX group, and the serum ALP activity of OVX group was significantly higher than that before operation( P＜0.05)，but no change was found in Sham group. As a result, models of osteoporosis were successfully set up in OVX group. New bone formation was determined in peri-implant area with good osteointegration in Sham group 4 weeks and 8 weeks after implantation. The new cementum was like bone cortex, and it became gomphosis with spiricle of implants.　No obvious gap was observed. The osteointegration went on well. In OVX group, a little new bone formation was found in partial peri-implant area, the structure was irregular and it was far from implants. Inflammatory reaction and a mass of connective tissue were observed around the interface of bones and implants. Implants broke up with bones, the gap was obvious and the osteointegration was bad. Conclusions：New bone formation was inhibited in peri-implant area in tibias of rats, which caused inadequacy of bone-implant osteointegration．