Abstract: The two kinds of by-products produced in TATB synthesis, extracted respectively by toluene and acetone, were separated by open-tube capillary electrochromatography （CEC） on a column coated with sol-gel DB-β-CD as stationary phase. The separation conditions were optimized including the value of pH, the concentration of buffer and the content of organic additives, obtaining the column efficiency of 10⁷ plates/m and high resolution. The method was demonstrated to be efficient by comparing with C（18）-packed column CEC method and high performance liquid chromatography （HPLC） method.