The calcified paddy soils in China cover an area of more than 270 thousand hectares.The content of CaCO₃ varies from 10-20% and the ratio of CaCO₃/MgCO₃ from 10-30%.The soils are compact in texture with calcarous concretions and, sometimes, calcareous hard-pan in profile. The soils are deficient in P, K, available B, Zn, Mo and Mn.The calcium in the calcified paddy soils mainly results from liming and irrigating water with high Ca content from karst caves. The conditions of calcium carbonate accumulation in the soils are the high pH value, low partial pressure of CO₂ and poor water permeability of the soils.On the basis of the content of CaCO₃ and estimation by ¹⁴C dating method, the formation of calcified paddy sail has a history for at least more than three hundred years.Because liming is one of the factors resulting in the deterioration of the soils, it is recom mended that more organic manure should be ahp1ied father than liming on the soils, at the some time microelement such as Zn, B, Mo,etc should also be applied.