Hantaviruses are etiologic agents of hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS) in the world. Various hantaviruses were isolated from HFRS patients and several different rodent species in the world. Four hantavirus isolates from Indonesia and three isolates from Thailand among 89 Bandicotas captured in Yogyakarta, east region of Sumatra island, Indonesia and at Chiang Mai in Thailand during 1996 were made through several passages in Vero E6 cells. Viral genome M segment from two Indonesian isolates and three Thailand isolates were amplified using hantavirus generic primers of the M segment and cloned into pCRII vector. The genetic differences were analyzed by comparison of partial sequence of the M segment and antigenic differences were made by IFA. Nucleotide sequence homology of two isolates BC 8, BC 34 from Indonesia and two isolates thai 1322, thai 1330 to Seoul virus was 99% and 96%, respectively, but Thai 1164 was 80%Thai 1164 strain has shown 95% homology to Thai 749 virus. In conclusion it is indicated that two different serotype hantaviruses, Seoul and Thailand, are cocirculating among Bandicota in Thailand, in contrast Seoul serotype virus is circulating in Indonesia.