Abstract: The porcine sera from intensive concentrated farms were examined by ELISA、LAT and IHA using the antibodies against seven diseases in 2006, including pseudorabies virus（PRV）,porcine reproductive and respiratory syndrome virus（PRRSV）,japanese encephalitis virus（JEV）,porcine parvovirus（PPV）,hog cholera virus（HCV）,porcine circovirus（PCV） and Toxoplasmosis. Analysis results indicated that average positive rate of immunity antibody of HC,PR,PRRS,JE,PP were 84.3%，78.3%,84.7%,58.0%,79.7%, separately. The PRRSV infected seriously with the unvaccined pigs' average infective rate of PRRSV was 55.1%, but average infective rate of wildtype PRV was only 17.7%. Coinfectons among PRV,PRRSV and PCV-2 were detected by the 541 serum samples from the 58 infected farms. The results showed that double or triple coinfections were very genenral, which made diseases more complicated and preventions more difficult.

Key words: PR; PRRS; JE; PP; HC; PCV-2; toxoplasmosis; serological investigation