To produce the instant marsh calm(Corbicula elatior) soup with abundant taste and flavor. optimum conditions of heating temperature and time for extraction were investigated. Excretion rate in a pre-treatment for excretion of estuary was 82% at 15% salt concentration for 6 hr and 95% at pH 7.5 for 10 hr. The contents of glycogen and amino-nitrogen were the most high levels in the treatments extracted at 9$0^{circ}C$ for 3 hr, at 10$0^{circ}C$ for 1.5 hr and at 11$0^{circ}C$for 1 hr. The contents of total free amino acids in the extracts treated at 9$0^{circ}C$, 10$0^{circ}C$ and 11$0^{circ}C$ were 367.05mg/100g, 472.23 mg/100g and 463.54 mg/100g, respectively and optimal temperature was above 10$0^{circ}C$. The mineral contents was the most high level for the extract treated at 10$0^{circ}C$ for 1.5hr. The results of sensory evaluation showed that tastes for the marsh calm extracts had no significant discrimination, while external appearances and flavors for the extract done at 10$0^{circ}C$ for 1.5 hr were excellent. The extracts at 10$0^{circ}C$ showed a little dark color and those at 9$0^{circ}C$ smell a little fish flavor.