Dissolved organic matter (DOM) is a focus and challenge in the field of water environmental research since it plays an important role in the restoration research of aquatic system. Ultraviolet-visible (UVVIS) spectroscopy and fluorescence spectrophotometer are often used as an effective way for extracting DOM characteristics. In the present research, spectral characteristics of DOM were studied in water samples from different locations of the Hongfeng Lake, a man-made deep karstic lake and a key drinking-water source for Guiyang City, Guizhou Province, and various components of organic matter distributed at different samples were identified. The UV-VIS absorption ratio values (E3/E4) for the water samples collected from the Hongfeng Lake ranged from 1.70 to 8.77,and in general these values at 10 m depth were higher than those at 5 m depth except site HWHDC, while the fluorescence ratio values (f450/f500) ranged from 1.38 to 1.52. It could thus be inferred that the main organic pollution was from terrestrial origin at present. It is found, however, that spectral characteristics of the water samples from sites HWHDC, BHHX and ZG are different from those from the other sites. In addition, the results indicated that the depth of water had correlation with the humification degree of organic matter.