The non-Newtonian behavior, dynamic viscoelasticity and optical rotation of schizophyllan solutions were measured with a rheogoniometer and polarimeter. Schizophyllan showed shear-thinning behavior below 0.3%, but plastic behavior above 0.5%. Gelation occurred for native and sonic degraded schizophyllan at concentrations of 0.8 and 2.0% at O"C, but melted when the temperature reached S"C, which was estimated to be a transition temperature. However, the dynamic modulus stayed at a large value during an increase in temperature up to 85ยฐC. A small decrease in the dynamic modulus of schizophyllan was observed upon addition of urea (4.0 M). A transition temperature was observed when the temperature of schizophyllan reached 60" in 0.1 N NaOH and in 85% dimethyl sulfoxide solution, respectively. Though the optical rotation remained constant during a decrease in temperature up to lSยฐC, it increased with further decrease in temperature. The thermostability of the dynamic viscoelasticity of schizophyllan may be essentially attributed to an intramolecular hydrogen bonding in aqueous solution. A possible mode of an intramolecular hydrogen bonding for schizophyllan was proposed.