A new solvent extraction system of Au by surfactant CTMAB-TBP-inert diluent-Au（CN）-2-H2O was investigated and established. The infrared spectra and the conductivities of loaded organic phases containing （Au） were recorded stage by stage. It was reported that in the presence of salting-out agents the pencent extraction of Au decreased, and the conversion of emulsions from W/O to O/W happened in the extraction processed. The results demonstrate that the extraction process of Au（CN）-2 is carried out by two steps. First, an associated molecule between CTMA+ and TBP, as (C16H33)（CH3）3N+·H2O·OP（OC4H9）3, is formed by dint of water molecule, then it will pull Au（CN）-2 into the organic phase based on the electro-neutrality.
