Some enzymatic properties of Cynthia roretzi v. (Drasche Korean : U-Rung-Shei) was studied by author and obtained the following results; 1. The optimum pH of the digestive gland amylase was 6.8-7.0 2. Activity of metallic ion on the amylase showed the following order; 10$^{-3}$ M M $n^{++}$>10$^{-3}$ M $Co^{++}$>10$^{-4}$ M $Mg^{++}$>10$^{-4}$ M $Ca^{++}$>10$^{-2}$ M Z $n^{++}$>10$^{-2}$ M P $b^{++}$ 3. The digestive gland enzyme inactivated at 70.deg. C. 4. When the enzyme concentration increase 2 times, the enzymatic activity also increase, but not propertionally. 5. The digestine gland amylase showed remarkably higher enzymatic activity than the intestinal amylase. 6. The digestive gland amylase from the ascidian showed remarkably higher enzymatic activity than the heptancreatic amylase from shell fish (Turbo (Batillus) Cornutus Solander).nder).nder).