Leaves of umbrella tree (Pandanus amoryllifolius Roxb.) contained several compounds that can be used as natural insecticide. It is containing poliphenol, flavonoid, saponin, volatile oil and alkaloid. However, lethal concentration of the leaves extract of pandamus tree was unknown. The objectives of the research was to determine the LC50 of the extract towards Aedes aegypti larvae. A 24600 ppm water suspension of the umbrella tree extract was prepared. A series of suspension was prepared by diluting 16.25 ml; 19.3 ml; 22.36 ml; 25.4 ml respectively to approximately 200 ml, and than transferred them into 250 ml glass aquaria. To each aquarium, 20 larvas were added and the volume of the mixtures was adjusted to 250 ml by adding distill water. Mortality of the larva was observed in 24 to 48 hours. Log probit analysis of the larva mortality showed that the LC50 were 2198.4655 ppm and 1669.1678 ppm for 24 and 48 hours respectively.