Abstract: Due to the similar floatability of talc and molybdenite, separation of these two minerals via flotation is the key element for recovering molybdenum from talcose molybdenite. Different depressing abilities of several types of Carboxymethyl Cellulose (CMC) from different resources were studied to investigate the influences of CMC's characters on their depressing ability, providing the exploratory research for choosing more effective CMC for the flotation separation of molybdenite from talc.