In order to detect the oil pollutants in soils and to protect the soils, the fluorescence characteristics for crude oil,diesel oil and machine oil were measured by the fluorescence spectrum analysis method.Firstly, the stimulated emission mechanism of organic molecules in oil was studied theoretically, then the fluorescence spectrum experiments for three kinds of mineral oil in water and soils were conducted respectively by a fluorescent spectrograph, and the fluorescence characteristics of different concentrations of the mineral oil were investigated.It is shown from the measured results that three kinds of oil in the soils and water can all emit intensive fluorescence as they are excited by UV rays, and the fluorescence spectra are located between 350 nm and 700 nm.When their concentrations in water and soils are in the range of 0.0-1.0 mg/kg, the relationship between oil concentration and fluorescence intensity shows a good linearity and the minimum detecting limits are 0.005 mg/kg in water and 0.01 mg/kg in soils.These results demonstrate that the fluorescent spectral analysis can be used in the detection and analysis of the concerned oil pollutants in soils directly or indirectly.