As an alternative of high toxic pesticide methamidophos product, safety problems existing in the use of acephate,a kind of agricultural products has been concerned by public. Tomato seedings under hydroponic conditions in this study as the research object. Mixed nutrient solution of 0.5 mg/L Cd^{2 +} and 1.0 mg/L acephate to study the rules of Cd²⁺ and acephate in tomato xylem fluid in different time by roots of tomato seedings absorb. The study found that Cd and acephate in nutrient solution could be absorbed through the root of tomato seedings by uptake through the xylem .The concentration of Cd in nutrient solution could promote the absorption and transportion by acephate, while the concentration of Cd could inhibited the transporation upward of acephate in nutrient solution of tomato roots.