Abstract: A method of ICP-MS coupled with extraction induced by emulsion breaking (EIES) was applied for determination of manganese,iron and lead in diesel oil. The diesel oil was emulsified with an acid surfactant (Triton X-114) solution in order to form a stable water-in-oil emulsion and then the metallic elements in diesel oil were fully extracted with nitric acid. Further,the emulsion was broken by centrifugation,yielding two separated phases. The metallic elements in the lower acidic aqueous phase were determined by ICP-MS using the internal standard method. The limits of detection (3S/N) and quantification (10S/N) were in the range of 0.008-0.083 μg·L-1 and 0.027-0.28 μg·L-1,respectively. The method was used to detect manganese,iron and lead in diesel oil,giving values of recovery in the range of 94.9%-106% and RSD (n=7) in the range of 0.66%-2.2%.