The paper deals with the inositol hexaphosphate contents and fractionation of organic P from three kinds of organic mannres and two kinds of paddy soils.The nutritional effecr of inositol hexaphosphate on the growth of rice seedlings was compared with that of inorganic phosphorus at the same P level.Inositol hexaphosphate was the main form of organic P in the organic manures and paddy soils.In pig and chicken feces,Ca-or Mg-inosirol hexaphosphate was up to 80% of the total organic phosphorus.However,in the paddy soils and cattle feces,Fe-inositol hexaphosphate was predominant in the total inositol phosphale.Fractionation of organic P indicac manures that the availability of organic P in organic manures was higher than in soils.In aseptic culture,inositol hexaphosphate had a better effect on rice seedling growth than inorganic phosphorus.