Tripura possess a rich source of ethnobotanically important plant species. Among them some weed legumes are known to have good potential as cover crops in agro-based forestry and rubber plantation areas. In the present paper, we highlights the contents of certain carbon and nitrogen metabolites in three selected weed legumes which grow luxuriantly around the Tripura state. Superiority of Cajanus scarabaeoides in carotenoid content with a total free amino acid 4.29 ± 0.27mg/ g. leaf fr.wt. is significant as ethnobotanicals besides its nitrogen fixing ability in the soil and potential cover crop.