Objective To study the key points and operative characteristics of establishment of the bone fracture models in mice and to analyze and compare the fracture healing characteristics of two chosen fracture models in mice in different time points post-operatively,in order to definite the advantageous fracture model in mice.Methods An open transverse tibial fracture with intramedullary needle fixation model and a closed transverse femoral fracture with intramedullary needle fixation model were selected,which were both established in C57BL/6 wild-type mice.The characteristics of bone fracture healing of these mice were serially analyzed and compared by X-ray,micro-CT and histomorphometry.The observations of mobility were also included.Time points were set by day 4,7,10,14,21,28 and 35 post-operatively.Results The one batch successful rate of model establishment was 94.2% on tibiae;no other fracture and displacement of fixation needle were observed.The one batch successful rate of model establishment was 80.0% on femurs;comminuted fractures or fractures outside the operation region were observed in 17.9% of mice and 14.3% of the fixation needles were found displaced proximally.Callus mineralized volume fraction and connectivity density of calluses on tibiae were significantly higher in comparison to calluses on femurs by day 10,14,21 and 28 postoperatively (P<0.05).A larger cartilage area was observed by day 7 and a larger bone area was observed by 10,14,21 and 28 postoperatively in calluses on tibiae when compared to calluses on femurs (P<0.05).The cartilaginous callus fraction reached peak level in tibial tissues by day 7 and in femoral tissues by day 10 postoperatively.The recover period from fracture in terms of mobility was shorter in mice operated by tibial fracture.Conclusions Comparing the two animal fracture models,the open transverse tibial fracture with intramedullary needle fixation model is better for the studies of bone fracture healing.