Citrullus lanatus (Watermelon) belongs to the family Cucurbitaceae. It is botanically called as pepo. This fruit contains Vitamins, aminoacids, Potassum and they are rich in lycophene, a carotenoid pigment. This pigment serves as a powerful antioxidant. Apart from these nutritional values, Citrullus lanatus has other bioactivities like Anti-microbial, Anti-giardial, Anti-Prostatic hyperplasia, Anti-inflammatory activities. Therefore in this study Anti-microbial activity and GC MS analysis has been carried out from the seeds of Citrullus lanatus.