Oil-contaminated pillars were prepared by spilling oil on soils’ surface. The weight loss of oil was determined by subtracting the pillars’ pre and post weight measured on an electronic balance. The aim of this paper was to investigate the change of oil’s volatilization mass in soils with time. The results show that the gasoline in soils volatilizes at a logarithmic rate with respect to time, and the diesel oil in soils volatilizes at a rate which can be best modelled as a linear of time. The volatilization coefficient of gasoline in grit exceeds that in loam, while the volatilization coefficient of diesel oil in loam is from 2.0 to 2.5 times higher than that in grit. Oils’ volatilization coefficients increase with the increase of oil content. Linear equation and binomial equation describe the relationships of gasoline’s and diesel oil’s volatilization coefficients with oil content respectively.