Abstract: Rock is a kind of dielectric. Since the rock is found to be capacitive, it should be discussed about the capacitive characters of dielectric. The electrical model of dielectric is established based on the rock capacitance obtained by primary voltage and secondary voltage during charging and discharging. According to the new model with capacitor and resistor as the dielectric, verification is carried out using the time domain and frequency domain experimental data of chalcopyrite, pyrite, glass, mica, amber and polyethylene capsules by interdisciplinary predecessors. It is further verified by comparison with the classical theory of permittivity. The results show that the electrical parameters of the new model are perfectly consistent with those of chalcopyrite, pyrite, glass, mica, amber and polyethylene capsules. The new model is suitable for all kinds of relaxation time, direct current and alternating current environments, and can also fully express the relations between various permittivity and electrical loss. The main conclusions are as follows:Dielectric is a leaky internal resistance-containing capacitor; It can be regarded as a number of parallel circuits containing internal resistance capacitor and leakage resistor; The impedance and equivalent capacitance of dielectric depend on the capacitance, internal resistance, dielectric resistance and frequency; Rock capacitance is one of the dielectric capacitance.