Abstract: This paper studies the fatty acid of different structure property relationship of trap agent of scheelite flotation. Four aspects of fatty acid collectors of scheelite trapping effect performance, including double bond number, from fatty acid alkyl carbon chain length of carbon chain isomerism, adding hydr oxyl, are calculated by measuring the adsorption of scheelite and thermodynamics of △G-pH to illustrate the possibility of the existence of this difference. The experimental results show that: the fatty acids of different structures of the collecting ability between collector on scheelite varies. The higher the unsaturated fatty acid unsaturation degree, the better the flotation effects; the carbon atoms number of fatty acid carbon chain is within a certain range; the scheelite flotation effect increases with the increase of the number of carbon atoms; hydrocarbon chain unsaturated fatty acid of the carbon chain isomerism effects better than unsaturated fatty acid of normal hydrocarbon chain in scheelite flotation; when the moleculars of fatty acids are intrduced into hydroxyl, flotation effects are worse than that of the hydroxyl without fatty acid.