Abstract: The influence of Pb mixed in soil on soybeans and hydroponic rice was studied.The distribution of Pb in the plant-soil system was found by experiments. It was found that the Pb mixed in the soil was only absorbed 0.1--0.3% by the plants, and the greatest part of the rest remained in the soil. From 90--98% of the Pb absorbed by the plants accumulated in the roots, which will increase as the content of Pb does in the soil, and 2–10% of the Pb absorbed accumulated in the stems and leaves. Less than 0.1% or none of the Pb accumulated in the edible part of the plants. The effect of toxicity of Pb on the growth and development of the plants was not serious, and no visible injuries exhibited, hut the photosynthesis of the soybean and the photosynthesis-transpiration of the rice were evidently inhibited. This shows that two physiological indices of the soybean and rice are pretty sensitive response to Pb.