In general, the electrical pulse induced resistance (EPIR) effect of perovskite manganite originates from the interfacial Schottky barrier between the metal electrode and the surface of sample. In this work, La0.5Ca0.5MnO3 (LCMO) ceramic samples are synthesized by solid state reaction and the transport properties, especially the EPIR effect are investigated using 4-wire measurement mode. Although the I-V curve of LCMO shows ohmic linearity under the 4-wire measurement mode at room temperature, a stable and remarkable EPIR effect can still be observed when the pulse voltage is more than the critical value. Through the comparison between the intrinsic EPIR under 4-wire mode and the interface one under 2-wire mode, we find that the intrinsic EPIR of LCMO has a smaller critical pulse voltage to induce the effect, but it has a better anti-fatigue property. The intrinsic EPIR effect is a novel one which is observed in rare earth doped manganites.