TaN thin films with copper doping were prepared on Ni Zn ferrite substrate by the reactive DC magnetron sputtering method. With different nitrogen content, the influences of Cu doping on the electrical properties of the samples were investigated by adjusting nitrogen content. The X ray diffraction (XRD) results show that Cu3N and CuN6 phases appear at 2θ of 54° and 57° in copper doping TaN thin films, respectively. The results caused by nitrogen content increase are that the square resistance and the absolute value of temperature coefficient of resistance (TCR) increase with the thickness decrease. Compared with the square resistance and the TCR of the TaN thin films without Cu doping, the square resistance and the TCR of Cu doping TaN thin films were improved effectively.