Effects of dolomite on chemical fractions and availability of phosphate in red and yellow soil of south Anhui Province were studied. Results showed that application of P fertilizer could improve the contents of total P and inorganic P significantly, while decreased the content of organic P. The correlations between the contents of available P and various fractions of inorganic P were best for Al-P, Fe-P and O-P second, and Ca-P worst. Al-P is the most important source of available P. As time passed by, the effect of dolomite increasing the content of Al-P was getting more significant.