Objective In order to explore the mechanism of stress-induced immune dysfunction,two kinds of animal models with depressed immune response under stresses were established.Methods\ The mice were divided into 3 groups: the restraint-stressed group,heat-stressed group and control group.The experimental mice were stressed by restraint and heat,respectively.After being stressed,the mice of each group were subdivided into two parts,one part was injected by Escherichia coli.The death rate of each group was calculated.In other of them,spleen indexes of the mice of each group were compared,and the histopathological changes were examined.Results\ The death rates of the restrained stress group and heat-stressed group were all higher than that of control group(P<0.005).The death rates were not significantly different between the restrained stress group and heat-stressed group(P>0.05).The spleen indexes of both the restraint stress group and heat-stress group were lower than that of the control group(P<0.05).The histopathological examination revealed white pulp decreased with disarrangement in spleen of stressed mice.Conclusion\ The mice models of stress-induced immune dysfunction have been successfully established and there may be a correlation between the spleen structural alterations and immune dysfunction.The changes are not significantly related to types of stresses.