The flotation of oxidized zinc ore was investigated by using α nitroso β naphthol as activator and octadecylamine as collector.The results indicated that the dosage of the activator and collector，the type and content of dispersant were the main affecting factors on the Zn grade and recovery from zinc oxide ore.The artificial mixture flotation tests indicated that the grade of zinc was up to 3826% from the initial grade of 2230%，and the optimal flotation recovery was found at 8790% using calcium lignosulphonate as dispersant after activation with α nitroso β naphthol at pH 95It implied that α nitroso β naphthol was an effective activator for the flotation of oxidized zinc ore.The results of IR spectrum suggested that a six membered ring coordinated from O to Zn was formed between α nitroso β naphthol and Zn2+ on the mineral surface，resulting in the enhancement of the hydrophobicity of the mineral surface.