Objective To investigate the cause and process of crack generation and propagation in fretting wear of bone and to study the fretting wear mechanism between prostheses and bones. Methods Conducting a fretting wear experiment system with a dried thigh bone and titanium alloy. Results Bone structures in fretting areas become loose and obvious cracks could be found in both longitudinal and cross -sectional planes of the bone. Conclusion Bone structures in fretting wear will induce fatigue failure and this will further cause loosening of prostheses.