Abstract: In order to develop a reclamation technology of dump in the east of Inner Mongolia open-pit mine,rationally utilize potassium releasing bacteria to improve soil fertility of the clay layer in the east of Inner Mongolia Grassland, and exploit its great potential as a substitute for mature soil,by using sterile laboratory static culture for pretreatment sample and equilibrium adsorption,the influence of potassium releasing bacteria on the potassium adsorption kinetics of two kinds of common minerals in the clay layer in the east of Inner Mongolia Grassland was studied in this paper. The results showed that ① the equilibrium potassium adsorption time of illite was shorter than that of potassium feld- spar,and the cumulative potassium adsorption capacity was larger. The potassium releasing bacteria significantly increased the accumulative adsorption capacity of illite,but had no significant effect on potassium feldspar. ② The potas- sium adsorption kinetics process of illite had the best fitting effect on the exponential equation,and potassium feldspar had the best fitting effect on the first-order kinetic equation. The potassium releasing bacteria had no significant influ- ence on the kinetics models of potassium adsorption and fixation processes of two minerals. ③ The potassium releasing bacteria significantly increased the speed of po-tassium adsorption and fixation of illite,and prolonged the equilibrium adsorption time. The effects of potassium releasing bacteria on the adsorption rates of potassium feldspar at different time periods were instable,and that on the equilibrium adsorption time of potassium feldspar was not significant. The potassium releasing bacteria in-creased the decrease rate of the adsorption rate of illite with time. The decrease rate of the adsorption rate of illite with time was faster than that of potassium feldspar. ④ The potassium releasing bacteria significantly increased the potassium adsorption capacity of illite in the fast and the medium-speed stages. The adsorp- tion time was 10% longer than that of inactivated treatment of illite. The potassium releasing bacteria had no signifi- cant effect on the adsorption time of potassium feldspar in all three stages. Therefore,potassium releasing bacteria sig- nificantly affects the adsorption kinetics of potassium in soil clay minerals,which is of great significance for the rational use of potassium releasing bacteria to improve the utilization rate of potassium fertilizer in soil clay layer in the eastern Inner Mongolia and to promote the clay layer as a substitute for mature soil.