Through investigating the expressions of cells apoptosis of vagina and uteri，to discus the mechanism of Pen Yan Tang curing Ureaplasma urealyticum.Methods:Young adult female mice of strain KM were used.Sixty-three mice were divided into 7 groups randomly to be observed and compared in the trial.The medicine were Azithromycin and Pen Yan Tang.All mice were given Estradiol benzoate subcutaneously on four occasions，at weekly intervals.The serovar 8 of Ureaplasma urealyticum was inoculated intravaginally into all of the mice except the normal group at the same time as the mice received the second dose of Estradiol benzoate.Results: 1)The IL-1β level of the model group was increased，the difference with normal group was statistically significant(P<0.05);The IL-1β levels of all the treatment groups had no significantly difference(P>0.05);The IL-6 levels of all the groups had no significantly difference(P>0.05); 2)The uteri cells apoptosis rates of all the groups had no significantly difference(P>0.05);The vagina cells apoptosis rate of the model group was higher than the other groups(P<0.05);the vagina cells apoptosis rates of all the treatment groups had no significantly difference(P>0.05).Conclusion:Pen Yan Tang can inhibit the growth of Uu.Pen Yan Tang could reduce the pathological damage to the host，inhibit the expressions of inflammatory factor and germ cell apoptosis.