It was the first time that a primer pairs derived from the 190KDa protein antigen gene of R. rickettsii were used to amplify SFGR DNA in ticks, tick ova, larva, tick faeces and rodent organs which were collected in Hebei, Heilongjiang, Hainan and Beijing. A 532bp fragment was respectively amplified from above samples. The results were partially in concordance with data obtained through rickettsiae isolation. It was suggested that PCR is a rapid, specific, sensitive and practical method for detection of SFGR in endemic foci.