The effect of local heterogeneity on the distribution of dielectric relaxation times was studied for concentrated solutions of poly(vinyl acetate) (PVAc) in l-methylnaphthalene (MN) and those of poly(vinyl octanoate) (PVOc) in toluene (Tol). The half widths A of the dielectric loss curves for the primary processes of those systems are compared with those of the PVAc/Tol system reported previously. The data indicate that ri decreases in order of PVAc/Tol, PVAc/MN, and PVOc/Tol systems if compared at the same temperature T/T-g where T-g denotes the glass transition temperature of solutions. The halfwidth of each solution increases with decreasing temperature. The loss curve is calculated by assuming a Gaussian distribution of the local concentration phi which results in the distribution of relaxation times girl. The calculated loss curves agree fairly well with the observed ones. The broadening behavior is also explained by assuming that Lambda is proportional to the amplitude of the local concentration fluctuation Delta phi times the slope of the phi dependence curve of the average relaxation time tau. This assumption leads to a linear relationship between Lambda and Delta phi>(*) over bar * (T - T-0)(2) where T-0 is the Vogel critical temperature. Using this relation, we have attempted to estimate Delta phi. Small-angle X-ray scattering was also measured on PVAc/MN solutions and found that the scattering intensity was lower than that for PVAc/Tol. This is consistent with the fact that Lambda of PVAc/MN solutions is narrower than PVAc/Tol solutions.