[Objective]To investigate the relationship between inoculation dose of staphylococcus aureus versus radiological and microbiological changes of rabbit tibial infection with bone defect.[Methods]Staphylococcus aureus(ATCC 29213) with total number of colony from 6?101 to 6?106 were prepared.The bacteria were injected in the tibia after an area of bone defect was made.The inoculated lesions were assessed for changes in radiological and bacteriological parameters at 3 weeks after infection.[Results]Development of significant histological and radiological signs of infected bone defect required an inoculum of at least 6?105 CFU/5 ?l.[Conclusion]These results suggest that strain staphylococcus aureus(ATCC 29213) induces the development of chronic rabbit tibial infection with bone defect,and that this model may be applied to identification of virulence factors in studies of posttraumatic osteomyelitis.