Abstract: Amylases II-1 and II-2 with molecular weights of 55.7 and 65 kDa, respectively, were purified to electrophoretical homogeneity from small abalone (Sulculus diversicolor aquatilis) by ammonium sulfate fractionation, Sepharose CL-6B, CM-Sepharose CL-6B, and Sephacryl S-100 chromatographs. They had optimal temperatures of 45 and 50 °C and an optimal pH of 6.0. The purified amylases were stable at pH 5.0−8.0 and 6.0−8.0, respectively. They were completely or partially inhibited by Hg2+, Cu2+, Cd2+, Zn2+, iodoacetamide, phenylmethanesulfonyl fluoride, and N-ethylmaleimide, suggesting the existence of cysteine at their active sites. Digestion tests against various polysaccharides suggested that the purified amylases II-1 and II-2 are neoamylases which can hydrolyze both α-1,4 and α-1,6 glucosidic bonds. Amylase II-2 might be an exo- and II-1 an endo-/exo-amylase.