Abstract: In order to apply P fertilizers properly and enhance the bioavailability of phosphorus, simulation experiment of soil column was used to study the effects of P rates on the contents of inorganic P forms and P availability of plough layers in cinnamon soil. Results showed that there was a markedly positive correlation between Olsen-P and P rates of plough layers in cinnamon soil. Phosphorus activation coefficient of soil was enhanced markedly with the increase of P rates. The highest contribution is Ca2-P among the inorganic P constituents, and then was Fe-P and the lowest was Ca8-P. As P rates were increased, Ca10-P content had no obvious variation, which was thought as a slack effective P source and would not be absorbed by crops in the future of some length. Calcareous P were the main forms of inorganic P in plough layers of cinnamon soil and the proportions of the constituents of inorganic P from high to low were shown as followed: Ca10-P, O-P, Ca8-P, Al-P, Fe-P, and the lowest was Ca2-P.