Aromatic hydrocarbons are important components in crude oil and source rock. Aromatic hydrocarbon compounds which are complex and stable may be used to make the oil/source contrast and recognize the oil and gas properties, and can also serve as primary indicators to the existence of oil and gas in geochemical prospecting for oil and gas. Three-dimensional fluorescent spectrum of a graph has the feature of "finger-print". Samples with different properties are different in three-dimensional fluorescent spectrum parameters, whereas the parameters of the samples from the same source have many common properties. Three-dimensional fluorescent spectra have a good indicative significance to the properties of oil and gas by analysis of the surface samples in some prospect areas.The oil and gas properties of the trap in depth may be inferred based on three-dimensional fluorescent spectra. Three-dimensional fluorescent spectrum is an effective indicator to oil and gas migration and properties for oil and gas surface geochemical prospecting.