Dufton and Hider secondary structure prediction rules have been successfully applied to soybean glycinin and β-conglycinin subunits. Despite the different amino acid sequences involved, a common distribution of secondary structure was detected throughout these subunits. Each amino acid sequence of the subunits along polypeptide of the acidic and basic subunits caused us to predict highly α-helix and β-structure, respectively. The solvent accessibility reduction ratio in the accessible surface areas of each subunit has been attempted to calculate, based on a set of average residue accessible surface areas of the 21 kinds of amino acid residue produced by Chochia. Beta and basic subunits had higher accessibility reduction ratio than a, a ' and acidic subunits, respectively. Their total gains in the surrounding hydrophobicity of subunits and the corresponding gain ratios have been attempted to compute, based on a set of their average surrounding hydrophobicity values produced by Ponnuswamy et al. Each tendency of their differences in the total gains and gain ratios among their subunits was similar to that in their accessibility reduction ratios.