Cymbopogon nardus is a plant of the Poaceae family which is an herbal plant that is used by the community as room and clothing fragrances, relieves wound pain, improves digestion, beautifies the skin and bites the body of mosquitoes. Several previous studies have applied Citronella plants (Cymbopogon nardus) as mosquito repellents. Mosquitoes are very annoying insects because they cause pain and pain, they can also cause skin lesions due to mosquito bites and infections. Sensible mosquito repellent in the form of spray, burn or liquid where chemical compounds are harmful to human health, namely propoxur, tranflutrin, bioaleterin, dikiorvos, dalletherine, octachiorophil ether. The purpose of this study was to see the bioactivity of plants in Serai Wangi (Cymbopogon nardus). The method used is a computational study using various bioinformatics applications. From the research it was found that the plants in Serai Wangi (Cymbopogon nardus) were very effective as mosquito repellents.