With the oil-polluted soils after converted from paddy field to upland field for different years in the Shenfu wastewater irrigation area of Shenyang as test materials, the concentrations of their oil pollutants were determined, and the microbial community structure was investigated by denaturing gradient gel electrophoresis (DGGE) and phospholipids fatty acid (PLFA) methods. The results showed that the proportions of total polynuclear aromatic hydrocarbons (PAHs) in total petroleum hydrocarbons (TPHs) and of high molecular weight PAHs in total PAHs increased with the increasing years of field conversion. Total phospholipid fatty acids (PLFAs) had a significant positive correlation with total TPHs, but no correlation with total PAHs. Both DGGE and PLFA analyses indicated that the community structure of soil microbes was mainly correlated with geographical location, and changed obviously when the concentrations of oil pollutants in soil increased to a definite level.