Abstract: In this paper, the absorbing, transferring and accumulating law of mercury in the farmland soil-plant system polluted by mercury have been studied. The mercury content in soil within the range of 3 km from the pollution source was the highest. Mercury in soils distributed chiefly in 0–20cm surface layer, it almost did not move to the lower layer.The plants can absorb and accumulate mercury from the soils and air. The symptom of plants made by mercury pollution at Hangu have not been discovered. It was positive relationship between the mercury content in plants and soils. The correlation coefficient of mercury content in soils and in rice straw was 0.816(n=7), and the correlation coefficient of mercury content in soils and in brown rice was 0.898(n=7). The content of mercury in different organs of crops was as follows: root>stem>leave>seed; and compared with mercury content of the various crops seeds were as follows: brown rice> sorghum>wheat. In the air polluted area by high concentration of mercury, the mercury content of aerial part of plant was higher than that of root. Mercury of soils and plants was emitted continuously into the atmosphere, then it deposited on the soil surface or was absorbed by aerial part of plant. The capability of diffusion to adjacent area is Small.