Carrageenan oligosaccharides prepared from -carrageenan by carrageenase from Pseudomonas alcaligenes. The oligosaccharides showed three spots on TLC and the degree of Polymerization of the C1, C2 and C3 spot were each 9.0$pm$1.0, 6.0$pm$1.5 and 2.5$pm$1.5, respectively. Each hydrolysates and spots-C1, C2, C3-were tested the several functionalities such as antimicrobial activity, anticavity activity and anticoagulant activity. The antimicrobial and anticavity activity of carrageenan hydrolysates and oligosaccharide fractions were very low, but the anticoagulant activity was identified in all samples.