Aiming at investigating molecular genetic characters and searching molecular marker-related growth traits in Xiangxi cattle, the mutations of bovine IGF–IR gene partial sequence were detected by PCR and gene sequencing, and PCR–RFLP was used to analyze population genetic polymorphism of IGF–IR gene. The results showed the expected 616 bp IGF–IR patial sequence PCR products was obtained, sequence analysis indicated that IGF–IR gene in Xiangxi cattle contained a total of 34 SNPs, in which, one SNP had been reported in previous study, while 33 SNPs were firstly found in this study. Two alleles (A and B) and three genotypes (AA, AB and BB) of g.551G>T locus in IGF–IR gene were detected in Xiangxi cattle, A allele was dominate allele, which were in moderate polymorphism, and fitted in Hardy–Weinberg equilibrium (P>0.05) in Xiangxi cattle population. The result of the association between polymorphism and growth traits indicated that g.551G>T locus had no significant influence on height, body length, heart girth and body weight of Xiangxi cattle (P>0.05).