Abstract: The separation technique of solvent extraction based on reversible chemical complexation can have high capacity and high selectivity for separating polar organic solutes from dilute solution. By using TOA and TBP as complexing agents, n - octanol, MIBK or kerosene as diluent, a series of extraction equilibrium experiments for phenolic aqueous solutions were carried out. In a wide - range of pH the effects of solutes, type and concentration of complexing agents, pH value of aqueous solutions and diluents on distribution ratio D are discussed. An expression of equilibrium distribution that includes chemical complexation and physical extraction simultaneously has been proposed.