Seaweed is a common name of marine algae, a group of species from the Protista kingdom, meaning they are not plants at all, even though they may look like underwater plants. They have therapeutic and nutritive properties as innovative, inventive sources of natural products. The bioactive compound obtained from this seaweed is having a unique structure and activity. The intention of this study investigated the presence of phytochemical constituents, Fuorescence analysis, invitro antioxidant activity, UV-VIS analysis and cytotoxicy nature of Gracilaria cervicornis . Phytochemical is naturally present in the seaweeds which biologically play a significant role. Phytochemical analysis showed the presence of alkaloids, phenols, Saponin, flavonoids, tannins, terpenoids, carbohydrate, protein, fixed oil and fat, amino acids. The fluorescence analysis revealed the pharmacognostical characteristics of selected sea weed.