Abstract: Lithium metaborate fusion pretreatment and inductively coupled plasma atomic emission spectrometry(ICP-AES) with internal standard method were used for the determination of SiO₂、CaO、MgO、Al₂O₃、Fe₂O₃ in diopside. The best analytical lines of the elements were determined. The interferences were eliminated by using matched matrix and background correction. The experimental results showed a good linear relationship with the linear correlation coefficient(r ≥ 0.999 5), the detection limits of the elements were 0.061%(SiO₂), 0.039%(CaO), 0.024%(MgO), 0.011%(Al₂O₃), 0.009%(Fe₂O₃), the precision of RSD were less than 5%, the recovery rates were in the range of 99.0%~101.8%. The proposed method was applied for the determination of real samples of diopside, and the results were basically consistent with those obtained by chemical analysis methods in other laboratories.