The polysaccharide of pycnorus cinnabarius was prepared

fractionated and characterized. By using the water as solvent and the alcohol as precipitant

six fractions of polysaccharide were obtained. All fractions and the unfractionated sample have been characterized by dynamic osmometry

VPO

ultracentrifugation

light scattering and gel permeation chro-matography. Modified Elias cloud-point titration method with a UV speclrophotometer was used to determine the cloud-point. It was found that water/acetone (89.82:10.18 by volume)is a θ-solvent for the polymer at 25℃. The relationships between molecular weight and intrin-sic viscosity[η]

unperturbed chain dimension

Second Virial coefficient A2 of polysaccharide in a θ-solvent at 25℃ were as follws From the result above the unperturbed dimension(h) was found to be 1.21×10-9M1/2(cm).It was found that the polysaccharide has the styomgest inhibition effect on S180 in mice. The relationship between the antitumour activity and their solubilities in water was dis-cussed.