Objective To investigate the regulatory mechanism of parathyroid hormone-related protein(PTHrP) in proliferation and differentiation of chondrocytes of condyle in fetal mouse. Methods Chondrocytes of condyle in fetal mouse were separated and cultured in vitro, the influence of PTHrP on proliferation and differentiation was observed. Results After two weeks′ culture in 0.01 nmol/L, 0.1 nmol/L, 1 nmol/L, 10 nmol/L human PTHrP, there was significant difference in the number of cartilage nodule formed between experiment group and control group (P0.05). Alkaline phosphatase(ALP) activity was significantly intensified in experiment group and control group(P