Seaweeds are considered an important source of bioactive molecules. The aim of this study was to characterize the enzymes concentration present in sea weeds of seaweeds. The algal species Gracilaria folifera, Hypenea masiforms (Red) and Sargassum longifolia, Turbinaria gonaidae (Brown) and Bryopsis, Caulerpa peldata (Green) was collected from the intertidal region at a depth of 1 m during March 2005 in of Mandabam Coast, Rameswaram, Tamil Nadu, India. Enzymes nitrate reductase, nitrite reductase, glutamine synthetase and glutamate dehydrogenase concentrations of sea weeds were estimated. Green algae Bryopsis has higher concentration of Nitrate reductase (12.5 ? 1.6 ng/gm). Brown algae of Sargassum longifolia showed maximum concentration of Nitrite reductase (7.21 ? 1.6 ng/gm). The red algae of Gracilaria folifera showed higher concentration of Glutamate dehydrogenase (5.01 ? 0.8 ng/gm). Brown algae of Turpanaria gonaidae has higher concentration Aspartate transminase of (2.1 ? 1.3 ng/gm) From the results, enzymatic extracts of the seaweeds might be valuable sources enzymes, which may be utilized for mankind and environment welfare.