The correlativity of soil Ca-P components and changes of phosphatase activity are studied by field experiment after fertilizing phosphates during maize growth. Results show as follows: The phosphates fertilized the soil mostly transformed to available P and Ca2-P during the initial and middle days of maize growth stages, and mainly transformed to Ca8-P during the post days of maize growth, and hardly transformed to Ca10-P. The high water quantity conditions are helpful to the transformation of soil phosphorus from the easily solvent form to the difficultly solvent form, the phosphates transformation efficiency decreases under low water quantity conditions and increases under high water quantity conditions; The phosphatase activity of soil rise during the initial and middle days of maize growth stages, and slowly descend during the post days of growth, water has smaller effect than fertilizer efficiency on phosphatase activity; The correlation of soil available P and Ca-P components is Ca8-P > Ca2-P, the correlativity of soil phosphatase activity and available P and Ca-P components is: Boot stage > Jointing stage > Waxy ripe stage > Maturity stage, soil available P and phosphatase activity have no correlativity with Ca10-P.