Quantity and intensity(Q/I)relationship of potassium (K) in three soils, a gray desert soil from Xinjiang, a dark brown earth from Jiling and a brown earth from Shandong, were determined at 5, 25 and 4090 to investigate the effect of temperature on K supplying power of the soils. With the increase of temperature, the AR° and △K° values increased, while the PBC value decreased. When temperature increased from 5℃ to 40℃, the AR° avlues of the gray desert soil, the dark brown earth and the brown earth increased from 0.0167,0.00074 and 0.0010 to 0.0348,0.0015 and 0.0014√mol·L^-1,respectively.