Abstract: In order to clarify the genolypes differenee of activation and utilization characteristics to inorganic Phosphorus, phosphorus efficient genotype 56 and Phosphorus inefficient genotype 60 were used. The potted soil experiment was employed to evaluate their differences in plant,shoot and root phosphorus content, root/ shoot ratio, inorganic phosphorus fractions under three inorganic phosphorus named Al-P、Fe-P、K-P. Results showed that shoot phosphorus content of phosphorus efficient genotype 56 higher than Phosphorus inefficient genotype 60; the availability of three inorganic phosphorus supplies to two oats genolype is K-P〉Al-P〉Fe-P; Phosphorus efficient genotype 56 had stronger ability to utilize and assimilate OH-Pi,dil.HCl-Pi than phosphorus inefficient genotype 60 in soil; the difference in the activation and utilization of inorganic phosphorus was shown on the two insoluble inorganic phosphorus supplies and it found that phosphorus utilization efficieney of phosphorus efficient genotype 56 was higher than that with phosphorus inefficient genotype 60 under three inorganic phosphorus.