Heavy metal pollutions in the soil have been an important content of its quality. The objectives of this study were to evaluate the potential risk of heavy metals and early warning analysis of agricultural soil in four counties, Northeast China. One method based on toxicity coefficients was applied to assess the potential risk of these heavy metals in soil. The results showed that average content of Cu, Pb, Zn, Cd, As, Ni, Hg and Cr in agricultural soil was lower than the first level standard of agricultural soil, and Cd led to risk was the most important factor, which 0.21% of the area was in the state of potential risk of elements Cd. And other heavy metals were not harmful to the environment, which potential risk of harm in descending order is E (Cd)> E (Hg)> E (As)> E (Ni )> E (Cu)> E (Pb)> E (Cr)> E (Zn); The other method is that the Cd pollutants can be calculated by the atmospheric dry and wet deposition, the irrigation water, the chemical fertilizer and the crops. There was a point on the assumption that the pollution caused by the atmospheric dry and wet deposition was worse than the pollution from irrigation water and chemical fertilizer. It is concluded that heavy metal pollution of Cd in the southeast of the study area will be getting worse within the next few decades by forecast warning analysis. Overall, some part of study area is in the state of potential risk and the Cd of soil is a major factor to control the retention of the heavy metals in the soil. According to analysis of their characteristics and the level of potential risk, there will not be great impact on quality by developing appropriate control measures timely.