In the study, the characteristics of the etched Zinc oxide (ZnO) thin films surface, the etch rate of ZnO thin film in Cl2/BCl3/Ar plasma was investigated. The maximum ZnO etch rate of 53 nm/min was obtained for Cl2/BCl3/Ar=3:16:4 sccm gas mixture. According to the x-ray diffraction (XRD) and atomic force microscopy (AFM), the etched ZnO thin film was investigated to the chemical reaction of the ZnO surface in Cl2/BCl3/Ar plasma. The field emission auger electron spectroscopy (FE-AES) analysis showed an elemental analysis from the etched surfaces. According to the etching time, the ZnO thin film of etched was obtained to The AES depth-profile analysis. We used to atomic force microscopy to determine the roughness of the surface. So, the root mean square of ZnO thin film was 17.02 in Cl2/BCl3/Ar plasma. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the plasmas.