Under the same field conditions, attenuation of organophosphorous pesticides (OPs) in the soil is directly associated with the structural characters of the pesticide per se. Relationships of half-life of OPs in flooded soil and dry soil with theoretical linear solvation energy, topological parameters, physic-chemical properties, quantum chemical descriptors and the Dragon descriptors were studied with the best subset regression analysis method. A series of QSAR models were thus developed. Results show that the models developed from Dragon descriptors were the best at explaining the mechanism of attenuation of OPs in the soils. The model analysis indicated that steric topological orientation plays a key role in attenuating process of OPs, no matter whether the soil is submerged or dry.