Abstract: A continuum overlapping model of cubic particles is introduced based on ge neralized lattice model of discrete overlapping particles for the dispersed ionic conductors. By using this model, the relationship between the concentration and the density of DIC system is found out. With the effective medium approximation(EMA), the effects of the particle size on the critical threshould and condutivity are studied and discussed.

Key words: effect of particle size, continuum percolation model, critical threshould