Marsh calm(Corbicular elatior)with a short-term storage in raw and a law-rate of utilization has been increasing the needs to develop new marsh calm processing products for a temporary mass treatment and long-term distribution, Therefore the processing conditions of marsh calm beverage using proteolytic enzyme hydrolysis were investigated. A partial hydrolysis at 6$0^{circ}C$ for 1 hour after adding 3% Alcalase as more effective than a hot water extraction to develop taste compounds from the marsh calm. The result of ommission test showed that nucleotides and their related compounds were contributed in the taste of the marsh calm hydrolysates rather than free amino acids. The taste of the hydrolysates was produced by association with these compounds rather than only one compound s the hydrolystes taste differently for the control when one of these compound was omitted. The hydrolysates were fractionated to molecular weight below 500 dalton to eliminate bitter taste and to improve it flavor from the hydrolysates, 0.05% bay leaf was more effective to improve the odor than other herbs.