The ionic conductivity of ferroelectrics (BaTiO3, LiNbO3 and KNbO3) and Al2O3 dispersed Li2CO3 composite solid electrolyte systems has been investigated using complex impedance analysis. The dispersion of second insoluble and unreacted phase has been substantiated by evidence obtained from X-ray powder diffraction and scanning electron microscope techniques. A considerable enhancement in the ionic conductivity has been achieved. The highest conductivity of 1.14 x 10(-5) (S cm(-1)) at 250 degrees C has been observed for 50 wt.% LiNbO3 dispersed Li2CO3. The conductivity is seen to be strongly dependent on the particle size, dielectric constant and the concentration of the dispersoid. A surface charge transfer mechanism at the interface is suggested to understand the formation of a space charge layer and so the microscopic conduction process.