Objective To study on the effect of indicator animals in plague surveillance throngh detecting F1 antibody against Yersiniapestis(Y.pestis)in indicator animals in wild rat plague foci,provide scientific evidence for plague control and determining the range of epidemic area.Methods According to investigation scheme of wild rodents plagne foci in Yunnan Province,indicator animals Canis familiarils and Felis catu(C.familiarils and F.catus)related to the plague were investigated in 75 villages,14 township and 10 counties around Yulong County,and living rodents were captured by cage,sera of indicator animals and rodents relevant to plague were simultaneously collected and detected for F1 antibody against Y.pestis using indirect hemagglutination(IHA).Results Seropositivity rate of indicator animals were 6.76%(202/2987),being 24.69% in C.familiaris and 24.69% in F.catus,there were statistical significance(X2＝87.32,P＜0.01)between C familiaris and F catus,the latter beingmore than the former.But F1 antibody of rodents sera were not detected,its seropositivity rate was zero.there was a statistical significance(P＜0.01)between indicator animals and rodents.Conclusions Through serocpidemiological survey of indicator animals,new wild rat plague natural focus has been confirmed in YuLong County and Gucheng District in LiJiang City,therefore,serocpidemiological surveillance of indicator animals is very important for plague control and prevention.