During the level season of Jialing river (from March to May),samples of seven representative sites of Chongqing urban areas are analyzed and compared by three-dimensional (3-D) fluorescence spectr a.The differences of 3-D fluorescence spectra are obtained from measurements in the sa me condition and related to the variations of dissolved organic matter (DOM) contents so that the y indicate the changes of water quality of Jialing River.Then the change regulations of three-dimensiona l fluorescence spectra are discussed in details.At last,the res ults show that the fluorescence peaks of samplings are mainly humic-like and protein-like peaks. Moreover,the average fluorescence indexes of samplings from March to May are 1.41~1.57,1.30~1.47an d 1.42~1.68, respectively.And according to the fluorescence index (f450/500),water pollutions mainly come from terrestrial sources during the sampling period.In addition,the difference of f luorescence index results from the influence of temperature,rain,geography and other factors.