In this study, reburning reaction characteristics of solid biomass fuel for NOx reduction including the kinetics was investigated to evaluate the reactivity. The reburning fuels are raw material and char of rice husk, and the experiment was conducted in Drop Tube Furnace(DTF). The experimental parameters and it’s ranges are as follow. Equivalence ratio is 0.95-O2 0%, reaction temperature is 800-1000℃ and initial NO concentration is 200-700 ppm. In order to analyze the characteristics of reburning, the NO conversion ratio, which is the ratio of initial NO concentration and NO reduction amount, was derived and analyzed for the characteristics of reburning under each condition. The rate equation for the rebuning of raw material and char of rice husk was derived, At this time, the activation energy of the rice husk raw material and its char were 72.21 kJ/mol and 104.43 kJ/mol, respectively. As a result of that, the reactivity of rice husk raw material is higher than it’s char.