Abstract: To address the issue that the Zn wettability on the surface of advanced high-strength steels(AHSS) was severely impaired and the quality of zinc coatings was adversely affected by the selective oxidation of Mn during the annealing process, the reduction reaction kinetics and product characteristics of AHSS under different temperature and atmosphere conditions were investigated in this study. Reduction reactions of the experimental steel were carried out using a ZRT-B thermogravimetric analyzer within a temperature range of 500-900 ℃, with hydrogen-nitrogen mixed gas in two variants: one without water vapor and the other containing volume fraction of 4.5% water vapor. The results show that the reduction kinetics curves are exhibited “S” characteristics, which could be divided into an induction period, an acceleration period, and a deceleration period. As the reduction temperature is increased, the induction period is gradually shortened. With increasing temperature, the morphology of the reduction products is transformed from porous iron to dense iron. When the temperature is raised to 800-900 ℃, internal oxides of Mn are formed in the subsurface region of the substrate under two kinds of reducing atmospheres. The the oxygen partial pressure is increased by the presence of 4.5% water vapor in the reducing atmosphere, which promoted the inward diffusion of oxygen ions. Since the rate of oxygen ion diffusion inward is much higher than the outward diffusion rate of Mn ions, the internal oxides is formed.