Different Kbearing minerals including biotite,muscovite and orthoclase were ground to 251~840 μm,151~250 μm,74~150 μm and <74 μm,and continuously extracted with tartaric acid and oxalic acid to study potassium release and its kinetics. Results showed that compared with 251~840 μm particle size,the release rate of biotite with particle size of 151~250 μm,74~150 μm and <74 μm increased by －9%,34%,129% and－21%,20%,152%,respectively; the release rate of muscovite increased by 246%,495%,566% and 288%,511%,610%,respectively; the release rate of orthoclase increased by 32%,167%,417% and 182%,675%,1 687%,respectively. It is indicated that the amount of potassium released from muscovite and orthoclase increased significantly with the decrease in particle size,while that of biotite decreased first and then increased with the decrease in particle size.