Through the discussion from a view different from the traditional, the correlations between UV 254 and organic matter monitoring parameters in the field of water supply and wastewater treatment was discussed, such as TOC, DOC and THMs precursors. According to the explanation of applicability in this paper, UV 254 can be used as a surrogate parameter. The measurement of UV 254 as a surrogate parameter has several advantages, such as inexpensive instrument, convenient operation, low operating costs, good correlations to the parameters surrogated, high accuracy and excellent data reappearance in multiple measurements. The application of UV 254 as an indirect parameter is quite valuable, especially under the current financial level of the operation and monitoring of the water and wastewater treatment plants and the laboratory research in China.