A glucan, GBW, was isolated from the alkaline aqueous extract of Glycyrrhiza uralensis Fisch. Its mean molecular weight was estimated to be 4 x 10(3). TLC, methylation analysis, periodate oxidation, Smith degradation, partial acid hydrolysis, KI--I2 reaction, IR and 13CNMR showed that GBW is a (1----4) linked alpha-D-glucan (6).