Abstract: To study the impact of IGF\|I gene on the growth of Tibetan pig and Yanan pig， a pair of primers was designed by sus scrofa IGF\|I gene sequence from GenBank（Accession number：DQ1211321），the total RNAs were extracted by using Trizol from the livers of Tibetan pig and Yanan pig and used as template to amplify IGF\|I gene by RT\|PCR，the amplified fragments were cloned into pMD19\|T vector and the recombinant plasmids pMD19T\|IGF\|I were constructed and sequenced. The sequencing results indicated that the IGF\|I gene consisted of 612 nucleotides，containing a complete ORF of 462 bp ecoding 153 amino acids. The two IGF\|I gene sequences shared high homology with the porcine IGF\|I gene reported by Muller, et al.，which had an identity of 100% in Tibetan pig and 9961% in Yanan pig. It shared 9961% homology between the Tibetan pig and Yanan pig IGF\|I gene. An A→G mutation occurred in the 258 bp of Yanan pig， but the corresponding amino acid was not changed.

Key words: Tibetan pig, Yanan pig, IGF\, I gene, sequence analysis