After alkaine hydrolysis, the body wall of Slicliopus varicyatus was fractionally pre-cipitatecd with alcohol, then oxidatively decoloured and purified with KAc, the elcctrophorelically pure polysaccharides SVI and SVIIwere obtained. The results of ultracentrifugal analysis showed that the sedimentation coefficients were S20w 3. 09 for SVI and S20w 2. 12 for SVII. The metachromatic reaction with reddish black I showed the metachromatic peaks of SVI and SVII were shifted to 514nm and 507nm, respectively. The molecule of SVI is composed of aminogalactose, glucuronic acid, fucose and sulfate (1:1. 21:1. 29:4. 62) and that of SVII is composed of fucose and sulfate (1.0. 99). And our results of Stichopus japonicus acidic mucopolysaccharide ultracentrifugation therefore suggests that the sedimentation coefficients is S20w 2. 12. The metachromatic reaction with reddish black I showed the metachromatic peak is 515nm. The molecule of Sjamp is also composed of aminogalactose, glucuronic acid, fucose and sulfate ( 1:1. 1:1. 20:4. 87)