A series of experiments, static light scattering, dynamic light scattering, and shear viscosity, have been performed to study the critical properties of micellar solution of sodium dodecyl sulfate (SDS) and butanol in an aqueous solution of sodium chloride in terms of the modified dynamical droplet model. The exponents nu and gamma for the long range correlation length and the osmotic compressibility were obtained as 0.736 and 1.374, respectively, in agreement with Fisher's renormalized Ising model. The experimental investigation on the dynamic critical behavior suggests that the modified dynamical droplet model, which assumes that the local fluctuations activated thermally behave as the physical clusters with a fractal dimension of d(f) = 2.49 and a polydispersity exponent of tau = 2.21, describes well the dynamical behavior of the SDS ionic micellar mixture together with an evaluation of the effective micellar size of 7-8 nm.