Abstract: In order to illuminate the cause for neurological sign and death in suckling piglets at a Bartha-K61-vaccinated pig farm in Hebei province, one wild stain of pseudorabies virus (PRV), named HBXT-2018, was isolated from the brain tissues of sick piglets and identified by PCR, Immunoperoxidase monolayer assay (IPMA), animal experiment and gene sequencing in this study. Experimental rabbits were subcutaneously injected with HBXT-2018 strain of 10⁵TCID₅₀, and they started to bite the inoculated sites at 24 h and all of rabbits died within 44-68 h. Neutralizing antibody titer of anti-PRV strain Bartha-K61 serum was lower than the dilution of 1:8, whereas that of anti-PRV variant serum was 1:58.9. Compared with Bartha strain, gB and gC nucleotide and amino acid sequences of HBXT-2018 had various mutations including single or continuous several base-pair or amino acid residue substitutions, insertion and deletion, and predicted antigenic epitopes changes happened in the amino acid sequences of gB and gC. Phylogenetic analysis based on gB, gC and TK showed that HBXT-2018 clustered in the same branch with those strains prevalent in China especially since 2011 whereas it was located at a different branch from Bartha strain and other PRVs in Europe and America. The results indicate that HBXT-2018 isolated in this study is a virulent strain with the same genetic characteristics as the PRV variants currently prevalent in China while it has a remarkably distant evolutionary relationship with Bartha strain. Anti-Bartha-K61 strain serum did not neutralize this isolate well, which suggests that the mutations in gB and gC might be related to the viral immune escape causing piglet pseudorabies in this pig farm.