In this work, assaying of minerals and pot experiments with the graminaceous crop-ryegrass, rice and barley as the indicator crops were carried out by using chemical methods and Electro-Ultrofiltration technique to study the varieties of soil K forms as well as their distribution invarious particle fractions of soils (yellow chao soil, yellow brown earth, grey chao soil and red soil) and their relations to the K-supplying power of the soils.