Abstract: The hemagglutinin（HA） gene of a strain of swine influenza virus （H1N1）, A/Swine/ GuangDong /711/2001, was amplified by RT-PCR. The PCR products were sequenced after cloning into pMD18-T plasmid and the sequence was compared with the HA gene sequences from others reference strains of influenza virus in GenBank. The result indicated that 1 771 bp fragment covered the complete HA open reading frame, and encoded 579 amino acid residues. There were 8 glycosylation sites in the amino acid sequences of A/Swine/GuangDong/711/2001. The 5 glycosylation sites were positioned at 27, 28, 40, 104 and 287 of HA1 gene, others at 21,153 and 213 of HA2 gene. Compared with typical strains of swine influenza viruses(H1N1), the glycosylation sites were not conservative. Among A/Swine/GuangDong/711/2001 and A/South Carolina/1/18, A/MD/12/91 and A/Swine/Wisconsin/238/97, the homology of the nucleotides were 93.9%,94.7% and 93.9% respectively. Phylogenetic analysis showed that A/Swine/GuangDong/711/2001 had a close relationship with A/South Carolina/1/18 and A/Swine/ Wisconsin/238/97.