Objective:To investigate the role of G protein coupled receptor kinase 2 (GRK2) interacting protein-1 (GIT1) in bone fracture healing. Methods:Femur fractures in GIT1 knockout (GIT1KO) mice (n=30) and WT mice (n=30) were performed. X-ray,micro-computed tomography imaging (micro-CT),immunofluorescence of PECAM1 were performed 7,14 and 21 days after fracture. Results:Fracture healing was delayed and blood vessel volume as well as number were decreased in GIT1KO mice compared to those in WT controls. Conclusion:GIT1 is an important signaling participant in fracture healing,with gene ablationleading to reduced callus vascularity and reduced osteoclast number in the healing callus.