Abstract: The extract flower of Averrhoa bilimbi was studied for its larvicidal and chemical composition against malaria vector mosquito, Anopheles barbirostris. The larvicidal assay was conducted to record the LC50 and LC84 values. The larva mortality was observed after 24, 48 and 72 h of exposure period. The LC50 value of extract were 8.892 ppm after 24 h exposure, 4.015 ppm after 48 h exposure and 540 ppm after 72 h exposure whereas the LC84 value of extract were 66.881 ppm after 24 h exposure, 27.836 ppm after 48 h exposure and 2.084 ppm after 72 h exposure. Totally 22 compounds were identified by GC-MS. The major chemical compounds were cycloeicosane followed by. Benzenedicarboxylic acid and benzenepropanoic acid. The results of this study showed that extract of Averrhoa bilimbi is inexpensive, eco-friendly and save for human sources of natural mosquito larvicidal agent to control and reduce population of malaria vector mosquito.