Terpolymers were synthesized by the condensation of p-cresol (p-C) and melamine (M) with formaldehyde (F) in the presence of 2M HCl as catalyst with varied molar ratios of reacting monomers. The electrical properties of p-CMF-1, p-CMF-2, p-CMF-3 and p-CMF-4 terpolymers were measured over a wide range of temperature (313-423 K). From the electrical conductivity of these terpolymers, activation energies of electrical conduction have been evaluated and these values lies in the range 6.36 x 10-20 – 8.23 x 10-20 J/K. The plots of log vs. 103/T are found to be linear over a wide range of temperature, which indicate that the Wilson’s exponential law = oexp. (Ea/kT) is obeyed. On the basis of above studies, these terpolymers cab be ranked as semiconductors.