The influence of phase-to-phase capacitance on fault component integrated impedance during internal and external region fault is analyzed. A new method for calculating the fault component integrated impedance which eliminates the influence of phase-to-phase capacitance current is presented. By subtracting the capacitive currents flowing through to other two phase from each phase fault component differential current， the fault component integrated impedance is only determined by line-to-ground capacitance. EMTP simulation results show that the calculation result of the new method is much more steady， only the line-to-ground capacitance is needed to take into account for setting. The setting rule is much precise， and sensitivity of the protection principle is improved based on the fault component integrated impedance.