Envelope (E) gene of Japanese encephalitis virus isolated from mosquito in Can Tho province, strain CTMP-7 was sequenced and compared with published E gene sequences of 52 strains of JEV isolated before in Vietnam and some countries of Asia. Established phylogenetic tree showed that this virus belonged to genotype I. Pairwise comparisons of the E gene nucleotide and deduced amino acid sequences between JEV CTMP-7 with certain isolates in Vietnam and some countries in Asia indicated that it had 94-96 percent similarity with LAH-2097-05 and LA-H07-05 (in Long An province), VN22 strains (in the North of Vietnam), JE-KK-1116 strain (in Thailand), M895 strain (in Cambodia), SC04-17 strain (in China), JaNar17-07 and JEV-254 strain (in Japan). The nucleotide sequence of CTMP-7 strain had only 87 percent similarity with RFVL strain (Japan) and 84 percent similarity with JKT9092 strain but there were not much divergence in amino acid sequence ( or