3-D Fluorescence Spectrometry analysis and sorption experiments of Acenaphthene (Acp), one of the polycyclic aromatic hydrocarbons (PAHs), were carried on in this paper. Under the experimental conditions, the optimized excitation/emission wavelength (λex/λem) was 280/320nm. The correlative coefficient of 0.998 and the relative standard deviation of 4.03%(n=5) could be obtained over the linear ranges of 0.025mg/L~1mg/L for the calibration curve. The sorption tests of Acp to surface sediment in Chongqing Section of the Yangtze River showed that the sorption isotherms were fitted with different types of model, including traditional linear partition model and Freundlich model. According to the fitted value of model, the sorption behaviors of Acp to the surface sediment was not affected by the single sorption mechanism but the combined action of linear partition process and surface sorption.