To study the Borrelia burgdorferi sensu lato(B.b.s.l) infection in ticks,rodents and livestocks at forestry of Hunchun,Jilin province. PCR was used to detect 5S-23S rRNA intergenic region of B.b.s.l in ticks and rodents,and the restriction fragment length polymorphism(RFLP) was used to type the positive samples.IFA was used to detect the IgG antibody in sera of livestocks.A total of 100 I.persulcatus ticks and 327 D.silvarum ticks collected in forestry of Hunchun were investigated.The infection rates in I.persulcatus ticks and D.silvarum ticks were 36.0% and 30.9% respectively.The specific DNA fragments of B.b.s.l.had been detected in Apodemus speciosus,A.agrarius,Clethrionomys rufocanus,Cricetulus triton and Eutamias sibiricus,with infective rates of 14.0%,8.3%,13.0%,25.0% and 33.3%,respectively.The results of RFLP for genotyping of the positive samples in ticks demonstrated that they were proved to be B.garinii and B.afzelii genotypes.About 200 sera of cattle and 203 sera of sheep were detected by IFA.The positive rates of serological detection in cattle and sheep were 27.5% and 31.5% respectively.The infection of B.b.s.l.had been detected among vectors,rodents and livestocks,all the three taches demonstrated that Hunchun forestry of Jilin province are natural foci of Lyme disease.