CoP/Insulator/BeCu composite wire incorporating a capacitor was prepared by chemical deposition. This new type of composite wire functions as an LC resonance circuit element by itself, in which large LC resonance giant magneto-impedance (LCR-GMI) effect was observed when the driving frequency approached to the LC resonance frequency. The properties of LCR-GMI in the composite wire with a length of 95 cm were investigated. Its LCR-GMI ratio and field sensitivity are 4875% and 046%/A·m-1 at the resonance frequency of 29 MHz, respectively, which are higher than those of the ordinary composite wire. When the carrier frequency deviates from the resonance frequency, LCR-GMI ratio decreases obviously, showing distinct selectivity of frequency. Meanwhile, we proposed an equivalent circuit model based on the characteristics of the LC resonance composite wire, and simulated the experimental curves. The simulation results agreed well with the experimental data. Using the equivalent circuit model, we analyzed the physical mechanisms of LCR-GMI and the influence of wire length on the LCR-GMI effect.