Studies on the possible routes of transmission of epidemic hemorrhagic fever (EHF) were conducted in experimental animals. Results showed five-ID50/ml of EHF virus (EHFV) suspension could infect rats through their damaged skin. Both gamasid mites and mower's mites collected from epidemic areas could naturally infect and transmit EHFV by biting and stinging, or transmit transovarially. EHFV excreted from the experimentally infected animals could be transmitted to normal ones by aerosol. Experimental rats could be infected with EHFV via damaged mucous membrane of the digestive tract. The above results suggested the main route of transmission of EHFV was via damaged skin. Mite-borne transmission played an important role in perpetuating natural foci of EHF in rats. Respiratory transmission of EHFV via aerosol also was a possible route of transmission under specific conditions. In general, EHFV could hardly be transmitted via digestive tract. All those mentioned above provided an important scientific basis for prevention of EHF.