As a universal concern about the monitoring of priority pollutants, polycyclic aromatic hydrocarbons(PAHs) have low content in the water environment. Because of its high fluorescence quantum yields, the fluorescence spectra of PAHs can be used to investigate PAHs concentration. Fluorescence spectra of four kinds of PAHs were analyzed with the method of three-dimensional fluorescence spectra, which can describe the characteristics of PAHs more detailedly than two-dimensional fluorescence spectra. Results show that phenanthrene, anthracene have three stronger fluorescence regions, and pyrene, fluoranthene have several and two fluorescence regions, respectively. The biggest fluorescence peaks of phenanthrene, anthracene, pyrene and fluoranthene are 250/364 nm, 250/402 nm, 240/372 nm and 286/462 nm, respectively. Under the optimum conditions, good linear work curve was obtained by this method to determine four kinds of PAHs. This method serves to the simultaneous analysis of multi-component PAHs in the source water on a method basis.