. Dengue fever is a disease caused by dengue virus and spread by Aedes aegypti as a primer vector and Ae. albopictus as a secondary vector. The vector control by using insecticide was commonly used, however, it caused vector resistance. Alternative ways of vector control is needed to overcome this problem. Microorganism like bacteria and fungi has potential effect to become insecticides and eliminate vector diseases. Hence, microorganism could be used as one of the alternative ways of vector control. One of potential fungi that has pathogenicity to mosquitoes was Beauveria bassiana. The purpose of this research was to found out about the effect of conidia B. bassiana concentration to mortality of A. albopictus. This study also aimed to observe mortality condition of mosquito (feed and unfeed) infect by fungi, potential horizontal transfer and chitinase activity produced by B. bassiana. Mortality data were analyzed by univariate test and followed by Tukey's analysis. The result showed that mortality of A. albopictus is influenced by concentration of conidia. There is no effect of mosquito condition on mortality rate, and there are no interaction between conidia concentration and mosquito condition. Mortality rate of A. albopictus in concentration 105 is 23.05% ,while mortality rate in 107 was higher, 31.47%, concentrtion 105 Chitinolotic indexs of B. bassiana is 1.67 and specific activity of enzyme chitinase is 1.0557 unit/mg.