Spatial distribution and correlation of soil phosphorus,inorganic phosphorus forms,and enzyme activities in loessial soil and dark loessial soil under different land uses were studied on the Loess Plateau of Gansu Province.Results showed that as the depth of soil layer increased,inorganic phosphorus decreased,as well as organic phosphorus in dark loessial soil in orchard and vegetable garden.However,total phosphorus in farmland and alfalfa land increased with increased soil depth.There was a very significantly positive correlation between soil phosphorus and organic phosphorus in 0—20 and 20—40 cm soil layers for each land use type,as well as between soil phosphorus and total phosphorus.In terms of the average inorganic phosphorus content,Ca₁₀—P,Ca₈—P,Al—P,Fe—P,Ca₂—P,and O—P were ranked in descending order.As the depth of soil layer increased,Ca₈—P,Al—P,and Ca₂—P in loessial soil decreased,but they increased in dark loessial soil in orchard,farmland,and vegetable garden.In terms of the correlation between soil inorganic phosphorus forms and enzyme activities,orchard,vegetable garden,farmland,wasteland,sea buckthorn forest,and alfalfa and tobacco lands were ranked in descending order.In terms of the correlation between soil inorganic phosphorus and soil enzyme activities,Al—P,Ca₁₀—P,Ca₂—P,Ca₈—P,Fe—P,and O—P were ranked in descending order.