Change and availability of soil inorganic phosphorus components were studied by long- term experimental in six typical soils. The results indicated that, in original soils, there were mainly 0 - P and Ca10 - P among inorganic phosphorus with low availability. In all no fertilizer soils, amount of total inorganic phosphorus were decreased obviously due to continual cropping, the fraction of decreased inorganic phosphorus were mainly Ca2 - P, Al - P and Fe - P . And in soils with P fertilizer application continually, amount of total inorganic phosphorus and its components were increased obviously by application of P fertilizer, among them ratio of Ca2 - P, Al - P and Fe - P increased more but 0 - P, Ca10 - P less. The results mean availability of most of accumulated P in soils by P fertilizer.