[en] The influence of dimethyl sulfoxide (DMSO) on the structure and properties of the dipalmitoylphosphatidylcholine membrane was studied at positive temperatures by a combination of X-ray diffraction and small-angle neutron scattering. Penetration of DMSO molecules into the lipid membrane was found to depend on the mole fraction of DMSO in an aqueous solution, X_DMSO. At X_DMSO > 0.08 the SO group penetrates into the bilayer polar region, thus resulting in structural alterations. At X_DMSO > 0.2 defects in the membrane surface are developed