Hantavirus is the etiologic agent of hemorrhagic fever with renal syndrome (HFRS). It has been known that the natural reservoirs of Hantavirus are not only field mice but also other animals in parts of the world. In this study, to research on the host range of Hantavirus, immunofluorescent antibody against Hantavirus was investigated in wild birds from 1991 to 1992, duck from 1991 to 1992 and squirrels (Tamias sibiricus) in 1990 in Korea. The results were as follows: 1. Of total 179 wild birds of 14 species, Emberiza elegans elegans and Passer montanus dy-bowsky were antibody positive. The positive rates were 3.92% (2 out of 51) and 1.64% (1 out of 61), respectively. 2. The antibody titers of wild birds were 1:16 and 1:64 in Emberiza elegans elegans, 1:16 in Passer montanus dybowsky. 3. The positive rate of antibody in ducks was 2.3% (3 out of 129). 4. The positive rate of antibody in squrrels was 48.10% (38 out of 79). According these results, we newly showed that passer montanus dybowsky, domestic ducks and Tamias sibiricus possessed the antibody against Hantavirus.