Two distinct hantaviruses have been isolated from Apodemus agrarius in 1976 and Rattus norvegicus in 1980 in Korea. Since our serosurveys conducted in 1994, a genetically distinct hantavirus from Apodemus peninsulae has been investigated. To isolate hantavirus from A. peninsulae captured in Korea, the lung homogenate of seropositive A. peninsulae inoculated Vero E6 cells. Viral antigen was detected in a progressively higher percentage of cells with subsequent passage after 80 days postinoculation. The new isolate from seropositive Apodemus peninsulae was designated Suchong virus after Suchong valley located in northeastern region of South Korea. Comparing with hantaan virus 76-118 strain, Suchong virus-1, 2, 3 and 4 showed the similarity of 71.0-91.8% at nucleotide and 90.9-94.8% at amino acid sequences in 231 nucleotides region of M segment, and the similarity of 75.1-81.0% at nucleotide and 97.5-100% at amino acid sequences in 237 nucleotides of S segment.