Abstract: Four different samples have been tested by fluorescence spectroscopy. Three of the tested samples are of different ruminants: goat, sheep and cow. The fourth sample is a mixture of cow's milk in several different breeds of cow. It has been found that the most appropriate excitation wavelength fluorescence method for investigate of milk in ruminants is 255 nm. This is due to the fact that only at this wavelength there is little difference in emission wavelengths between goat and sheep milk. Emission wavelengths of small ruminants vary considerably in emission wavelengths with that of the cow, which belongs to a class in cattle. In this case, an essential point in the fluorescence spectroscopy with respect to testing cow's milk is that the milk taken from a cow breed differs in wavelength of fluorescence with that which is a mixture of several breeds. This fact means that the method of fluorescence spectroscopy is suitable for determining the quality of milk from the selected breeds, if that is the desire of farmers. We consider that an efficient analysis of the raw milk of ruminants separately proven method of classical fluorescence. With analysis by synchronous fluorescence not observed shift in emission wavelengths in comparison between the goat and sheep milk.