Abstract: Studies of the flotability of pure sample in Jinchuan and ore in Yunnan have been made. In order to obtain visible evidence of the presence of flotability by which finely microscope photographs were taken. The result showed that: the effect of the flotabilty by type and dosage of depressants, is to improve the ultra-fine mineral facilitate floated; sodium silicate were good dispersant, and combined depressants of CMC and KN had been used in the flotation; Combined collectors had no relationship to the flotability for serpentine minerals in this flocculation of the ultra-fine mineral.