In the present study, the three-dimensional fluorescence spectra of River A with great flow rate were investigated. The results showed that there existed three unambiguous peaks in the excitation-emission matrix of River A at λex/λem of around 230/340, 280/320 and 250/450 nm respectively. The fluorescence intensity varied significantly and had sharp fluctuation sometimes. But the CODMn of the samples remained quite stable. This study indicated that fluorescence technique could demonstrate the pollution in the water bodies with great flow rate and furthermore make up for the deficiency of the conventional parameters related to organic pollution, i. e. invalidation to exhibit the components of pollutants. It is a good tool for the early-warning of the water quality.