IGF-1 gene is an important regulating factor that has a growth-promoting effect on the growth hormone.IGF-1 gene promotes muscle cell differentiation in the muscle cell formation process.IGF-1 gene also regulates the growth of skeletal muscle during skeletal muscle growth.In addition, IGF-1 gene plays an important role in the formation of mammals and poultry embryos, and the process of postnatal growth.The IGF-1 gene has been implicated as a candidate gene for the regulation of pig growth traits.We analyzed exon 3 of IGF-1 gene polymorphism in Tibetan miniature pigs (n =128) by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing.