Porcine reproductive and respiratory syndrome virus (PRRSV) is a notable threat to the pig industry. Long-term epidemiological investigations and genetic variation analyses of PRRSV isolates benefit PRRSV prevention and control. In our study, 43 PRRSV strains were successfully isolated from the lungs of sick pigs, and the genetic variations of these isolates were analyzed. Phylogenetic analysis showed that the isolates belonged to PRRSV2 and that lineage 8 (8.7) subgroup III strains remained the dominant type circulating in South China. In addition, sequence alignment analysis identified many novel deletions and mutations in the Nsp2 and GP5 genes. Furthermore, phylogenetic analysis showed that highly frequent recombination events of PRRSV between different lineages might occur in Guangdong Province. These results may help to elucidate the epidemiology and genetic variation of PRRSV isolates in Guangdong Province. Keywords: GP5; Nsp2; phylogenetic analysis; sequence alignment; porcine reproductive and respiratory syndrome virus (PRRSV).