Abstract: To study immediate early 180 （IE180） gene of pseudorabies virus (PRV) and its function，IE180 gene was amplified by PCR method with designed specific primers, and then IE180 cloning vector was successfully constructed. After sequence determination, IE 180 gene sequence and amino acid sequence were compared and analyzed by using DNAStar software among seven published PRV reference strains. The results showed that the CDS region of IE 180 gene consisted of 4425 bp, coded 1474 amino acids，the gene and amino acid sequence homologies between HB-98 strain and reference strains were 98.4% to 99.1% and 97.8% to 98.4%. Phylogenetic tree analysis demonstrated that HB-98 strain was genetically closely related to TNL strain（AF352564.2）.

Key words: pseudorabies virus; IE180 gene; cloning; sequence alignment