Abstract: The flotation behavior and mechanism of benzyl malonic acid collector with combination use of hydroximic acid were studied by single mineral tests. The results showed that the recovery of minerals increased by combined use of benzyl malonic acid and hydroximic acid. When the dosage of combined collector is 1000g/t and the ratio of benzyl malonic acid and hydroximic acid is 4:6, on the condition of pH=7-9, the maximal flotation recovery of calamine was gained which was 75.6%. And while at pH=4-8, the dosage of combined collector reached 500g/t and the ratio of benzyl malonic acid and hydroximic acid is 2:8, the flotation recovery of hematite reached its maximum of 95.6%. The cooperation mechanism of combined collector was studied from the coordination chemistry perspective. From the results, interluding and cascading adsorption were existed between minerals and combined collectors.