Abstract: To study the epidemiology characteristics of major viral disease of porcine in Zhejiang province, a total of 1 118 clinical samples in the latest four years were collected, and viral pathogens were detected by PCR or RT-PCR. It showed that the mean infection rates of PRRSV, CSFV, JEV, PCV2, PRV, PPV, PEDV and TGEV were 51.71%, 15.71%, 27.16%, 50.80%, 1.99%, 84.40% and 9.00%, respectively. Among these pathogens, PRRSV, CSFV and PCV2 were most commonly detected during all the four years, which were still the most important porcine viral pathogens in Zhejiang province. The prevalence of PRV and PPV had been declining these years, indicating these diseases have been controlled effectively. Increase in detection rate (up to 39.29%) of JEV in aborted fetus was observed in the beginning of 2011. Remarkable increasing of detection rate of PEDV in newborn piglet occurred in February 2011, which caused heavy economic loss. In conclusion, PRRSV, CSFV and PCV2 are still the key pathogens for prevention and control in Zhejiang; moreover, multiple infection and emergence of new virus mutant are one of main factors that contributes to the increasing complexity of porcine disease．

Key words: major viral disease of porcine, epidemiology analysis, PCR, RT-PCR