The present study was focussed to know the biochemical composition in haemolymph , thoracic, chelate and non- chelate muscles of crabs inhabiting marine (Ocypode brevicornis) and estuarine (Scylla serrata) environment. To compare the nutritive value of crabs from different environment (estuarine and marine) and thereby encourage an increase in the consumption and utilization of these species. The results obtained in the present study have demonstrated that, crab inhabiting both marine and estuary water were highly nutritious in terms of protein, carbohydrate, and lipids. From which marine crab recorded the highest in protein, carbohydrate and lipids than estuary inhabiting crab. The variation is because of their geographical area, the environmental factors and their available food resources.