Abstract: The soil potassium supplying characteristics of 19 representative plow layer soil samples from Shanxi Province were studied by laboratory analysis and pot biological exhaust experiments The results were summarized as follow: potassium contents of various forms, soil potassium minimum soil K level value,as well as the amount of K uptake by crop varied greatly among the soils selected from Shanxi Province The differences have been seen among soils from different soil type and among soils from different regions The value of minimum soil K level and the amount of total K uptake by crop were important characters for soil K supplying power evaluation Long term supplying power of potassium of tested soils from Shanxi Province showed a decreasing tendency moving from south to north, according to different region Long term supplying power of potassium from different soil types showed the order: red clay soil, fluvo aquic soil loessial soil, cinnamon soil castano cinnamon soil, catanozem