The aim of the present study is to investigate the correspondence between volume transitions of scleroglucan gels and the reported conformational properties of the uncrosslinked polymer chains. The swelling behaviour of scleroglucan gels in binary solvent consisting of water and dimethylsulphoxide (DMSO) was investigated by first crosslinking aqueous scleroglucan in cylindrical tubes. The resulting cylindrical gels were cut into small pieces and subsequently equilibrated for several days in the DMSO/H20 mixtures with weight fraction of water, Wn, ranging from 0.0 to 1.0. The diameters of the gel pieces were observed using a calibrated phase contrast microscope. The experimental results obtained at T = 20°C show one volume transition at Wn = 0.1-0.15, and another at Wn = 0.8-0.9. The volume transition at Wn = 0.1-0.15 correlates with the reported dissociation of the scleroglucan triplex into random coils in mixed DMSO/water solvents at the same value of W n. The reduction in gel volume for Wn<0.1 is caused by the decreased mean-square end-to-end distance of the elastic segments in the dissociated random coil compared to the triplex state. The second gel volume transition at Wa = 0.8-0.9 occurs at the same value of Wn as the intra-triple helical transition in DMSO/water mixtures. This transition arises because of differences in the molecular interaction between polymer and solvents. We found that the location of the second volume transition shifted towards smaller Wn with increasing temperature. This is consistent with the reported stabilisation effect of DMSO on the low-temperature intra-triplehelical transition. The present study indicates that the two macroscopic volume transitions of scleroglucan gels reflect the conformational properties of the non-crosslinked polysaccharide chains.