Abstract: Latent infection is one of the most important obstacles for prevention, control and eradication of pseudorabies in the swine industry. In this study, a pig pseudorabies virus (PRV)-latency model was established by vaccinating PRVfree piglets with commercial PRV inactivated vaccine, followed by challenge with a genetically marked PRV strain gG-/LacZ⁺.Then the latency was reactivated by administration of dexamethasone. The distribution of PRV in the tissues of latently infected and re-activated pigs was studied by immunohistochemistry SABC staining with antibodies against β-galactosidase. The results showed that β-galactosidase positive cells were mainly found in the nerve tissues (cerebrum, cerebellum, brain stem, trigeminal nerve and optic nerve) and other tissues (tonsil, lung and kidney), and the quantities of positive cells decreased along the time post gG-/LacZ+ infection. After administration of dexamethasone the numbers of positive cells increased in these tissues.