Non-ion surface active agent can be separated from its solution of water by heating to its cloud point. A new method for the determination of zinc in mineral samples by flame atomic absorption spectrophotometer after phase separation and extraction making use of its cloud point was studied in this paper. The conditions of phase separation and extraction such as using Triton X-100 as phase separation agent, and octanol to drop the cloud point, and the influence of acidity and the number of times for oscillating were discussed. The detection limit was 0.005 microg x mL(-1). This method has been applied to the determination of zinc in ores with satisfactory results.