Soil phosphate diffusion characteristics and impacting factors are investigated by ³²P trace method of different soil texture. Results show as follows： the soil P diffusion coefficient increases markedly with the increase of soil water content, their relation being described by the correlation of the exponential; the soil P diffusion coefficient increases with the increases of soil clay content; the coefficient also increases with the increase of temperature, with the temperature effect on the soil P diffusion coefficient being described by the temperature coefficients of the P diffusion coefficient; the soil P diffusion coefficient increases markedly with the increase of P application quantity in soil; the effect of soil volume weight on the P diffusion coefficient is in relation to soil texture. such that for fine-texture soil, there is an increasing trend in the P diffusion coefficient with decreasing soil volume weight, and for light-texture soil, there is an increasing trend in the P diffusion coefficient with the increasing of soil volume weight.