The purpose of the present work was to evaluate the proximate composition, minerals content (Na, K, Ca, Fe, Mg, Cu, Zn, Mn), simultaneous quantification of water soluble vitamins (like ascorbic acid, thiamine, riboflavin, niacin, pantothenic acid, pyridoxine & folic acid) by HPLC of three different grasses viz. Cynodon dactylon, Apluda mutica and Eleusin indica. The result showed the highest calorific value of C. dactylon (124.031 ± 1.154 kcal/100g) which was also found to contain highest amount of protein and carbohydrate. An appreciable quantity of carbohydrate was estimated in the aerial parts of E. indica (17.762 ± 0.122%). E. indica had the highest potassium content (2.207 ± 0.006 mg/g) and calcium content (6.023 ± 0.002 mg/g). The sodium content ranged between 0.049 – 0.289 mg/g. The aerial parts of E. indica (274.945 ± 0.085 mg/100g) contained a very good amount of vitamin C. The water soluble B vitamin content in these plants under investigation ranged between 0.009 to 12.133 mg/100gm. In conclusion, the results indicate that these IAS can be utilized as food supplement.