Objective To observe the spatial and temporal expression patterns of FGFR3 gene and analyze the potential roles of FGFR3 during fracture healing and explore the technique of in situ hybridization of paraffin sections of bone tissue. Methods The fracture model of mouse tibia was established by the standard methods. The expression of FGFR3 mRNA was studied by in situ hybridization during the various stages of bone repair. Results There was faint FGFR3 positive-signal in the cytoplasm of prehypertrophic chondrocytes in soft callus on day 5. FGFR3 mRNA was strongly expressed in prehypertrophic chondrocytes and hypertrophic chondrocytes in soft callus on day 7, but disappeared on day 14, 28 because chondrocytes was replaced by osteoblasts. Conclusion FGFR3 mRNA was strongly expressed in prehypertrophic chondrocytes and hypertrophic chondrocytes in the fracture callus, which shows that FGFR3, a gene that regulates the proliferation of chondrocytes during bone development, may participate in the regulation of differentiation of chondrocytes during fracture healing.