Abstract:Neuropeptide Y（NPY）plays an important role in the activity of body feeding，and is the most potent endogenic orexigenic factor in mammals. In order to understand the structure and the function of NPY gene in the largemouth bass（Micropterus salmoide），the NPY’s cDNA of northern and Florida subspecies of largemouth bass were cloned by RT-PCR and RACE techniques. The result revealed that the NPY’s cDNA in two subspecies all contained an ORF encoding 99 amino acids and 5′-UTR of 52 bp. Using PCR and genomewalker technology，a 3 561 bp and a 3 565 bp DNA sequence of of NPY gene were acquired from northern and Florida subspecies of largemouth bass respectively. Sequence analysis indicated that gene from both subspecies contained 4 exons and 3 introns. By bioinformatics analysis with MATINSPECTOR，the basic transcriptional regulatory elements such as TATA Box，CAAT Box，CCAAT Box，and GATA Box were found in the promoters of both subspecies. Six single-site base differences between the two genomic NPY DNA sequences of 2 subspecies were discovered，4-base insert segments were identified in promoter sequence of Florida subspecies compared with the northern one. The homology of NPY genes with other species was also compared，the largemouth bass shared the highest nucleotide homology with mandarin fish and grouper，reached 90% and 88% respectively，and the amino acid homology were 93% and 95%.