Atomic oxygen (AO) exposure effects on magnetron sputtered Zr-Ti films have been performed by ground simulation instrument under different doses up to 1 x 10(21) ions/cm(2). XRD, Raman spectrum, FE-SEM, XPS depth profile, and nano-indentation characterizations were applied to study the structural and mechanical properties upon AO treatments. The as-received films show crystallization and morphology variation with substrate temperature. Upon AO treatment, preferred oxidation and erosion of Zr on the top surface and invariant oxide thickness was revealed. Moreover, films with different structure was verified to have different erosion resistance, i.e. those with poor crystallization presented best AO resistance while (0 0 0 2) textured films shown the worst. With the micro modification upon AO, macro properties of sheet resistance, hardness and modulus evolved. (C) 2014 Elsevier B.V. All rights reserved.