The flotation performances of four tertiary amines (DRN, DEN, DPN and DBN) on kaolinite were studied in this paper. All the four tertiary amines show very good flotation effects on kaolinite, and DEN does the best, with the highest flotation recovery of 92 %. In the acid pH scale, four tertiary can float kaolinite well because their cationics absorb onto the surface of kaolinite by electrostatic force; with the increasing of pH, the content of cationics was decreased to result in the lower flotation recovery. On the basis of Zeta potential, the surface of kaolinite is mainly electro-negative in the whole pH region, and its Zeta potential is remarkable increased after kaolinite was affected by four tertiary amines. Both the results of FT-IR spectra and Zeta potential show that four tertiary amines are absorbed onto the surface of kaolinite by electrostatic force. The flotation differences of four tertiary amines are due to the electronic effects and space steric effects of the substituents belonging to N atom in the amine molecule.