Abstract: Two strains of 97-7-2C and 97-9-2A. were isolated from the liver of the diseased Trionyx sinense of Taiwan polulat ion. After artificial infection by these two strains, the diseased rate and mortality rate were all 100% , in the young turtles of 10 ~ 15g body weight. Through the cultivation and physica-l biochemical reactive determination, 97-7-2C was identif ied as Yersinia enterocolitica, 97-9-2A. was identified as Y. pseudotuberculosis. They can cause septicemia in turtles. The alterat ive pathological changes were happened signif icantly in liver, kidney and intestine signif icant ly , but most seriously in intestine. The results from 20 drug selection testings indicated that , the Y. enterocolitica is sensitive to gentamycin, and trimethoprim, Y. pseudotuberculosis is sentive to trimethoprim and furantoin.