This strdy was performed to investigate the effect of chitin, chitosan and dithiocarbamate chitosan against cadmium accumulation. The Scapharca subcrenata were divided into four independent groups which were one control and three experimintal groups by camium alone treatmint or chitin, chitosan and dithsan and dithiocabamate chitosan which cadmium. Samples were analyzed by Varian 30/40 atomic absorption spectrophotometer. The results obtained were as follows;1. The cadmium concentration in water were isgnificantly decreased in three experimental group compared with that of control group (P<0.05)2. The cadmium concentration in muscle of S. srbcrenata in cadmium alone treatment group were similar to that of the chitin treatmint group, but chitosan and dithiocarbamate chitosan treatmint groups were significantly decreased (P<0.05)In conclusion, this study revealed the effect of chitin chitosan and dithiocarbamate chitosan against cadmium accumulation. It exhibited the highest effect at dithiocarbamate chitosan treatment group.