This paper deals with sixteen typical calcareous soils (pH 8.09-8.69 and CaCO₃, content 2.95-15.8%), i.e. sierozem, chestnut soil, dark loessial soil, yellow cultivated loessial aoil, old manaial loessial soil, black loessial soil, and yellow fluvoaquic soil sampled, respectively, from Gansu, Shanxi, and Henan provinces of China. The scheme developed by Jiang Baifan and Gu Yichu was employed for inorganic-P fractionation and the results show that the total amount of inorganic-P in the calcaerous soils tested is 550 ppm on average, in which Ca₂-P, Ca₈-P, Al-P, Fo-P, O-P, and Ca₁₀-P account for 1.34%, 9.91%, 4.27%, 4.40%, 10.9% and 69.1% respectively. The regression analyses between different forms of inorganic-P and P uptaken by plants indicate that the availability of Ca₂-P is surely recognized, and the P uptaken by plants is mainly Ca₂-P; Ca₈-P, Al-P, and Fe-P are also available forms of inorganic-P; while Ca₁₀-P is unavailable.