Zr-17Nb alloy has been introduced as a candidate for spinal ?xation rods because of its excellent mechanical properties and biocompatibility, low magnetic susceptibility, appropriate initial Young's modulus, remarkable deformation-induced variation of the Young's modulus, good ductility and relatively small springback. It has been recognized that nanotubular surface modification via anodic oxidation on metals is an efficient approach to highly improve biocompatibility of metallic implant. It is thus necessary to understand the formation of nanotubular arrays on Zr-17Nb alloy and carry out the evaluation on the nanotubular arrays. Electrochemical anodization was applied to modify the Zr-17Nb alloy surface to promote the bonding of alloy to human bone. Nanotubular arrays were formed on the surface of Zr-17Nb alloy by applying a 70 V constant potential in a glycerol electrolyte containing 0.35 mol/L NH₄F and 5%H₂O (volume fraction). XRD, SEM, HRTEM, EDS and XPS were used for the structural, morphological and compositional analyses of the nanotubular arrays. Results showed that during anodic oxidation process, the oxidation and dissolution rate of Zr were almost consistent with those of Nb. By extending the anodization duration from 10 min to 120 min, the diameter of nanotubes increased from about 20 nm to about 67 nm, and the length of nanotubes increased from about 2.4 μm to about 6.8 μm. After annealing at 450 ℃ for 60 min, the nanotube films were converted from amorphous to crystalline, mainly composed of orthogonal phase zirconia (ZrO₂) and orthogonal phase zirconium niobium oxide (Nb₂Zr₆O₁₇). The elastic modulus of the nanotube films decreased and the hardness increased. At the same time, the contact angle was reduced and the hydrophilicity was improved after annealing. Results demonstrate that highly ordered nanotubular arrays could be fabricate on the Zr-17Nb alloy. It is promising that nanotubular surface modification could be an efficient approach for enhancement of the biocompatibility of the alloy.