Natural Organic Matter (NOM) plays a major role in the formation of undesirable organic by-products following disinfection/oxidation of drinking water. It is suspected that most precursors to disinfection by-products (DBPs) are humic although non-humic substances have not been studied and are suspected of also contributing to DBPs. NOM reacts with many of the disinfectants used to treat drinking water, such as chlorine, chioramine, and ozone, to form a variety of DBPs. Many of these DBPs have adverse health effects in humans (i.e. carcinogenic or mutagenic effects). The primary DBPs of concern include the trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitrile (HANs). The Spectral Fluorescent Signatures (SFS) technique was developed for the identification of the humic acids (HA), fihlvic acids (FA) and non-humic substances by fluorescence. The SFS is the total sum of emission spectra of a sample at different excitation wavelengths, recorded as a matrix of fluorescent intensity in coordinates of excitation and emission wavelengths, in a definite spectral window. For the characterization of NOM in raw water, and determination of DBP formation reactivities, samples were prepared using river HA and FA, soil HA and FA and peat HA and FA in varying concentrations from 0.5 to 10 ppm. UV-2 54, TOC, DBP formation potential, SF5 tests were conducted on each matrix of samples.