Abstract: The results of different group of people and animal surveyed in national EHF surveil- lance points in 1991-1993,were summarized in this article.It proved that different kinds of epidemic area have the characteristics of periodicity and season, and of the space distribution was unbalanced and relatively stable;that the main source of infected EHF is Rattus Apodemus, and Rattus norvejicus in resodemtoa;, other animal carriers should be studied; that the colony as the main source of infected EHF amoutnts,density,rate of virus carrier,always changed with years,seasons and areas,obivously,they are relatively stable;and that in epidemic areaa the index of rat virus carriers ass main source of infec-tion has positive relationship with EHF morbidity in local area,and it also points that before the epi-demic peak,regarding local art virus carriers as main source of infection as rarget to prospect epidemic trend and intensity.The above result may act as importnas reference for health administration to make policy of EHF prevention.