In this paper, trisodium phosphate (TSP) was utilized for the flotation separation of fluorite from barite. Microflotation results showed that good floatability of both fluorite and barite was obtained at around pH 8.5 using sodium oleate (NaOL) as a collector. TSP showed a selective depression for barite, and flotation separation of fluorite from barite was achieved using TSP as a depressant and NaOL as a collector. Zeta potential measurements indicated that the addition of TSP prior to NaOL did not prevent the adsorption of NaOL on fluorite surface while it prevented NaOL to adsorb on barite surface.