Abstract. The insulin-like growth factor-I (IGF1) is a peptide growth factor that exerts mitogenic and metabolic activities, which are regulators of growth, survival and cell differentiation in a number of cell and tissue types. To elicit its effects, IGF1 must bind its receptors. The insulinlike growth factor 1 receptor (IGF1R) is similar to insulin receptor (INSR) and it mediates the growth-promoting effect of IGF1. The IGF1R gene, therefore, was selected as a biological candidate gene for growth, body composition, metabolic, and skeletal traits in animals (Rothschild et al. 1997). By now, no polymorphism of yak (Bos grunniensL) IGF1R gene is reported. In the present paper, the partial exon 1 region of IGF1R was screened to detect the SNPs in Chinese yak breeds. Associations of SNP of IGF1R with growth traits were analysed.