In this work, we investigated to the etching characteristics of the TiN thin film in He/BCl3/Cl2 plasma. The etch rate was measured by the gas mixing ratio, the RF power, the DC bias voltage and the process pressure. The maximum etch rate in He/BCl3/Cl2 plasma was 59 nm/min. The etch rate increased as the RF power and the DC-bias voltage was increased. The chemical reaction on the surface of the etched the TiN thin films was investigated with X-ray photoelectron spectroscopy (XPS). The intensity of Ti 2p and N 1s peaks are varied during etching process. A new peak was appeared in He/BCl3/Cl2 plasma. The new peak was revealed Ti-Clx by Cl 2p peak of XPS wild scan spectra analysis.