Dig-DNA probes of hemorrhagic fever with renal syndrome vinus M S gene fragment were prepared by PCR and random primer labeling, The probes had speciality to HFRSV-RNA and could detect 10pg RNA by RNA-DNA dot-blot hybridization. The results of hybridization showed that positive reactions were found in 5, 10 chigger mites groups from antigenic positive rats, 10 mites group from antigenic negative rats, 10, 50 free chigger mites, and hung of antigenic positive mice 100mg, 500mg. But negative reation in 5 mites group from antigenic negative mice.