Objective To study the effect of Shengguzaizaosan on experimental fracture healing. Methods Thirty six-month-old Chinchilla rabbits were made the models with 3 mm bone defect in the middle of two-side radius and were divided randomly into 3 groups: Shengguzaizaosan group(group A, n=10), Xianlinggubao group(groupB, n=10) and control group(group C, n=10). Five rabbits were sacrificed 14 days and31 days after operation respectively. The double marks with tetracyslin hydrochloride were given on the 4th day and the 5th day for the first mark and on the 11th day and the 12th day for the second mark in the rabbits sacrificed 14 days later,and on the 20th day and the 21st day for the first mark and on the 28th day andthe 29th day for the second mark in the rabbits sacrificed 31 days later. The samples were taken to make the bone histomorphometry study. Results When compared group A with group C, there were significant differences(P＜0.01) in osteoid area density, osteoid mean width, active osteoblastic surface, mineralization surface and dynamic parameters after 14 days,and in mean width of mineralization callus, active osteoblastic surface and mean depth of lacunae after31 days. There was a approximate effect between group B and group C. when compared group B with group A, there were significant differences(P＜0.05) in osteoclastic index,mineralization surface,bone formation rate after 14 days, and in osteoid surface,mean depth of lacunae and bone formation rate after 31 days. Conclusion Shengguzaizaosan can increase osteoid,accelerate mineralization rate and bone formation rate, and reduce mineralization lag time at early period of fracture. It can increase mineralization calluswidth and resorption of osteoclast at later period of fracture. To some extent, shengguzaizaosan can accelerate the experimental fracture healing.