The purposes of this study were to preliminary builtup the abundancedeficiency index(ADI)of soil available P(OlsenP)(SAP)and determine the appropriate phosphorus application rates(APAR)of different available P abundancedeficiency level soil for alfalfa in the North of China.The method of regression equation between soil available nutrient content and relative yield of the treatment with complete nutrients except one，the improved scheme for the grading of soil available nutrients abundancedeficiency，and the new applied formula based on “nutrient balance and projected yield minus soil fertility yield” for determining the appropriate fertilizer application rates were employed.The results showed that the ADI of SAP in the Northeast Plain of China for the first to fifth and the 6~11th level were ＞26,14～26,7～14,4～7,2～4 and 0～2 mg/kg,respectively.The ADI of SAP in the Inner Mongolia Plateau of China for the first to eleventh level were＞28,16～28,9～16,5.2～9,3.0～5.2,1.7～3.0,1.0～1.7,0.6～1.0,0.3～0.6,0.2～0.3 and 0～0.2 mg/kg,respectively.The ADI of SAP in the Northwest Oasis of China for the first to fifth and the 6~11th level were ＞20,12～20,7～12,4～7,24～4 and 0～24 mg/kg,respectively.The ADI of SAP in the Loess Plateau of China for the first to fifth and the 6~11th level were ＞29,15～29,7～15,4～7,2～4 and 0～2 mg/kg,respectively.The ADI of SAP in the Huanghuaihai Plain of China for the first to third and the 4~11th level were ＞13,4～13,1～4 and 0～1 mg/kg,respectively.When the projected yield of alfalfa hay is 15 t/hm2，the APAR for the first to eleventh level soil are 0,45,90,135,180,225,270,315,360,405 and 450 kg/hm2,respectively.