The characteristics and conductive mechanism of Ta/SiN x /Ta:SiN x /SiN x /Pt resistive random access memory (RRAM) are investigated. Compared with Pt‐doped devices with the same structure, the Ta‐doped devices produce lower operation current in a high resistance state and a larger on/off radio. Furthermore, reliability tests show that the Ta‐doped RRAM has good data retention ability and endurance. Ta clusters are observed in the Ta‐doped SiN x layer through the transmission electron microscope. Also, the X‐ray photoelectron spectra indicate that additional Si dangling bonds and tantalum nitride are present in the Ta‐doped SiN x film. Based on the structure of the device, material analysis, and electrical characteristics, a model is proposed to explain the influence of the doped Ta on resistive switching behavior of the device.