Soil samples were taken from 0~30 cm layer from selected plots with various fertilization treatments from a 10 years fixed site field trial in the National Purple Soil Fertility and Fertilizer Efficiency Monitored Base.Kinetics of K adsorption and native K desorption of the soil samples were studied.Results showed that K⁺ adsorption and desorption equilibrated in 24~32 min and 46~64 min, respectively, and the capacity of K⁺ equilibrium adsorption and desorption were 14.1~19.2 cmol kg^-1 and 11.6~17.5 cmol kg^-1, respectively.Correlation analysis indicated that soil cation exchange capacity (CEC) and clay content were important factors that affected the time and the capacity of K⁺ equilibrium adsorption; soil CEC and exchangeable K content were important factors that affected the time and capacity of K⁺ equilibrium desorption.As mentioned above the effects of long-term different fertilizer application on soil CEC, clay content and exchangeable K content affected the time and capacity of K⁺ equilibrium adsorption and desorption in purple soil.