Nb-1 wt% Zr polycrystalline and single crystalline samples were submitted to annealing, at pressure of 2.5 x 10-8 Torr and subsequently annealed in an oxygen atmosphere for three hours, in a temperature of 1170 K in oxygen at partial pressure of 5 x 10-5 Torr. Internal friction measurements as a function of temperature were performed between 300 K and 650 K, using a torsion pendulum inverted Kê-type operating in a frequency oscillation in the hertz bandwidth. Three internal friction peaks, which were assigned as Nb-O, Zr-O and Nb-N peaks were observed in oxidized single crystal sample and the relaxation parameters of the three peaks were obtained.