On the basis of the principle of Bratch`s electronegativity equalization, we calculated group partial charges and group electronegativities for nonionic surfactants with Pauling`s electronegativity parameters by using numerical calculation method. From calculated output, we have investigated structural stability of micelle, characteristics of hydrophilic and hydrophobic groups, and relation between CMC(Critical Micelle Concentraion) and group partial charge and group electronegativity of hydrophilic and hydrophobic groups for nonionic surfactants. We have known that CMC by micelle formation depends upon group partial charge and group electronegativity of hydrophilic and hydrophobic groups for surfactants. Also, the structural stability of micelle in H_2O solution is related to the electric double layer by the hydrophilic group of nonionic surfactants with H atoms in water. CMC is diminished by the decrease of repeating units in hydrophilic group at constant hydrophobic group and is diminished by the increments of alkyl chains in hydrophobic group at constant hydrophilic group for nonionic surfactants. In conclusion, CMC is diminished because there is no electrostatic repulsion and is diminished of Debye length by the increments of partial charge of hydrophobic group.