We report a new method of evaluating the adhesion of Al2O3-doped (2 wt.%) ZnO (AZO) thin films. The AZO films were deposited by DC reactive magnetron sputtering on plastic film (PET: polyethylencterephthalatc) at various sputtering pressures, power, and reactive gas-flow ratios. The adhesion test of the films was carried out using the nanoindentation system. The fracture point as determined by the load-displacement curve occurred at the time of separation between the thin film and the substrate. The integration value of load and displacement to the fracture point is defined as the degree of adhesion (S-w). The AZO films showed that adhesion increase as sputtering power increases and sputtering pressure decreases. (c) 2007 Elsevier B.V. All rights reserved.