Objective: Establishing a mouse femur bone defection model. Methods: Three 8-week-old female C57BL /6J mouse were used in this experiment. A hole with 1mm diameter was drilled on the distal femur. Then, the sulfonated polyetheretherketone(PEEK) with 1 mm diameter and 5 mm length was implanted into the femur marrow cavity. Micro-CT was used to reconstruct the bone microstructure and observe the implant position. Results: The health condition of mice with bone defection is good post-surgery and can survive until sacrifice. The movement of them is unlimited. The photos show that the implantation is fine placed in the femur marrow cavity. There is not any obvious damage. 3D reconstructed micro-CT images show that the position of implantation is fine. Conclusion: The mouse femur defection model was successfully established in this work.