In order to investigate the process and kinetics for the thermal oxidation of micron zirconium powders, the particle size distribution, micromorphology, elemental content and phase characteristics of the zirconium powders were studied by laser particle size analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The oxidation process at different heating rates was studied by thermogravimetry and differential scanning calorimetry (TG-DSC ). The kinetic parameters and reaction model were obtained. The particle size of zirconium powders was in the range of 15-46 μm, with irregular particles. The main phase of zirconium powder particles was metallic Zr. The oxidation process of zirconium powder can be divided into the four stages including initial oxidation, accelerated oxidation, vigorous oxidation and reaction equilibrium. The non-isothermal oxidation process followed the random nucleation and subsequent growth model function with the integral expression . Further, the activation energy E_a and pre-exponential factor A for the thermal oxidation reaction was 175.83 kJ·mol^-1 and 1.91×108 s^-1, respectively. The reaction rate constant k=1.91×10⁸ exp (-2.1×10⁴/T).