Abstract: Fourteen bacterial strains with potential lipase activity were collected from a refrigerators of a meat factory in Kunming,Yunnan Province,China.The strain showing the highest lipase activity was selected for lipase assay and named KM1.Based on morphological characteristics and 16SrRNA gene sequence analysis,KM1 were identified as Yersinia enterocolitica KM1.It showed that the optimal fermentation condition were 13 ℃,pH7.2,54 h,and the lipase activity was increased from 1.8 U/mLto 3.1 U/mL.The enzyme was stable at 25 ℃,pH7.2—10,and the optimal temperature and pHof the enzyme were 37 ℃ and 9.0,respectively.The enzyme showed good thermal lability,only 18% of the original activity was remained by incubation at 75 ℃ for 15 min.The substrate specificities of the lipases toward various p -nitrophenylwere were examined.The higher hydrolytic activity was obtained with C4-C12 p -nitrophenyl esters,with the highest activity toward pnitrophenyl caprylate (C8).The lipase exhibited good tolerance to low concentration of organic solvents (acetonitrile,methanol,ethanol and DMSO),it could keep nearly 60% activity even at 50% methanol.