Abstract: Oceanic oil spill incidents occur from time to time making it extremely important to establish a new identification method based on Pb isotope information. This method involves dissolving the crude oil in organic solvent (CH₂Cl₂), which is a strong polar solvent, and then digesting by microwave with HNO₃-H₂O₂ as the oxidant. The concentration and isotopic compositions of Pb (²⁰⁸Pb/²⁰⁶Pb, ²⁰⁸Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁷Pb) were measured under the optimum conditions of Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The accuracy and precision were also studied. The results show that the method is accurate, with a relative error of less than 5%, and a precision with RSD less than 2% (n=3). The dwell time for different Pb isotopes was also optimized by using Pb standard solution in order to improve the accuracy and get the best integration time. The concentrations of Pb in crude oil from Bohai, Nanhai and other countries was measured, and the concentration range of Pb in all crude oil was 37.99-1213.00 μg/kg demonstrating obvious differences. Meanwhile, the ratios of different Pb isotopic compositions were measured and further processed by cluster analysis by taking ²⁰⁸Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb as independent variables. It could be seen that the crude oil from different areas can be classified, especially the Nanhai oil. The study could provide some assistance for other identification of oil sources by preliminary screening.