A universal primer PCR(UPPCR) , PCR-RFLP and PCR- SSCP had been screened for a molecular biological method that permitted the rapid identif ication of fish pathogens among them. The results showed that a universal primer PCR technology was available with specif ic primers from conserved regions of bacterial 16S ribosomal RNA genes. The bacteria tested included some common causative agents of f ish diseases such as Aeromonas hydrophila , Yersinia ruckeri , Vibrio anguillarum, Flexibacter columnaris, beta-Streptococcus, Pseudomonas f luorescens. The approach allowed the bacteria above and Escherichia coli and Bif idobacterium catenulatum detectable w ithout any alterations of the experiment condit ions. However, this study also found that the identification of species of bacteria tested depended on the combination of UPPCR and SSCP( PPCR-SSCP) , which was better than that of UPPCR and RFLP( UPPCR-RFLP) and made rapid diagno sis of fish disease pathogens possible.