The method known as sensitive crystallization was utilized to distinguish between types of milk. Three con centration of copper chloride were studied (0,1; 0,25and 0,5 g/plate) in combination with three types of milk (raw, B and C) each in three concentrations (0,01; 0,025 and 0,05 g/plate). All combinations for each milk type were prepared in triplicate. It was observed in these 27 possible combinations that milk had a definite modifying effect in the mode of formation of copper chloride crystals. The method was found to be sufficiently sensitive to distinguish between the types of milk studied particularly at the concentrations 0,05 : 0,5 and 0,025 : 0,5.