This year, we will establish a DNA-Chip system that could be applied to the diagnosis of porcine respiratory disease complex (PRDC) including Porcine reproductive and respiratory syndrome (PRRS), Swine influenza virus (SIV), Pseudorabies virus (PR), Porciru respiratory corona virus (PRCV), porcine circovirus type II (PCV II), Salmonella, Mycoplasma hyopneumoniae, Streptococci species, Toxigenic pasteurella multocida, Bordetella bronchiseptica and Actinobacillus pleuropenumoniae. We will analysis the nucleic acid seguence of those 11 pathogens and design the primers and specific probes. The specific probes will be spotted to the DNA-Chip and the specimen will be confirm the results by the PCR/RT-PCR and hydridization pattern. Finlly, we will evaluate the results by testing the sensitivity and specificity.