目的　探讨分离自青藏高原改良绵羊体内的鼠疫杆菌的生物学特性。方法　主要包括细菌形态观察、糖醇类发酵实验、毒力因子检测及毒力测定。结果　该被试菌株具备 F1、Pst1、Pgm及 vw4个毒力决定子 ;其主要生化特性为鼠李糖 (- )、甘油 (+ )、脱氮 (+ )、麦芽糖 (+ )、阿胶糖 (+ )、密二糖 (- ) ;ML D为 10 0 0个菌。结论　该菌株毒力较强 ,其生化型为青藏高原生物型 Objective To investigate the biological characteristics of Yersinia pestis isolated from sheep in the Qinghai-Tibet Plateau. Methods include bacterial morphology, sugar alcohols fermentation test, virulence factor detection and virulence determination. Results The test strains had four virulence determinants of F1, Pst1, Pgm and vw. The main biochemical characteristics of the tested strains were rhamnose, glycerin, denitrification, maltose and gelatin, +), The major disaccharide (-); ML D is 100 bacteria. Conclusion The strain is highly virulent and its biochemical type is of the Tibetan Plateau type