The complete cDNA sequence of Siniperca chuatsi insulin-like growth factor-Ⅰ(IGF-Ⅰ) was isolated from liver and cloned by means of RT-PCR, rapid amplification of cDNA ends(RACE). A 1 784 bp IGF-ⅠcDNA sequence contained a 233 bp 5'-untranslated region, 990 bp 3'-untranslated region and 561 bp open reading frame(ORF), which encoded 186 amino acids with a signal peptide of 44 amino acids, a mature peptide of 68 amino acids, and an E peptide of 74 amino acids. The mature peptide included B, C, A and D domains. The E peptide analysis showed that S.chuatsi IGF-Ⅰbelonged to Ea-4 type. The amino acid sequence similarity of S.chuatsi IGF-Ⅰwas 81%-99% with that of other vertebrate IGF-Ⅰs, indicating that IGF-Ⅰwas relatively conserved in vertebrate evolution. The IGF-ⅠmRNA expression in different adult tissues were analyzed by real-time quantitative RT-PCR technique, and its highest expression in the liver, and high expression in kidney, brain, hindgut, skin, gonad, but low expression in stomach, spleen, foregut, gill, heart, muscle were revealed. These results may provide molecular base for further study on its developmental expression and growth regulation.