Abstract: A certain copper ore in Yunnan Province with the grade of only 0.47% Cu and oxidation degree of 23.02%, in which the content of harmful alkaline gangue mineral on flotation is high while the mineral composition is simple, belonging to refractory mixed sulfide-oxide copper ore with low grade. Conditional experiments on flotation of such ore were conducted aiming at the characteristics of it. The results show that: under the combination of butyl xanthate and ammonium butyl aerofloat (2:1) as collectors in dosage of 150 g/t, the grinding fineness of 80% -200mesh and sodium sulfide(Na2S) as activator in dosage of 500 g/t, copper concentrate with grade of 22.79% Cu and recovery rate of 86.04% were obtained by adopting the closed-circuit process of “one roughing -one scavenging - three cleaning”, providing a powerful reference for the development and utilization of a low-grade refractory sulfide-oxide mixed copper resources.