Objective To study population genetic characteristics of Mongolian Gerbils in Zhejiang Laboratory Animal Center.Methods 27 loci of two colonies were determined with biochemical markers.Results The two colonies had high level of genetic diversity and low degree of genetic similarity.Compared with the original colony,the biological purifying colony had 17.86% gene lost,but the two colonied did not show apparent genetic differentiation(F ST<0.05).Conclusion The population deviated from Hardy-Weinberg equilibrium(P<0.05).