Abstract: OBJECTIVE To establish an effective method for simultaneously determining the contents of essential oil and impurities in Olibanum. METHODS The amount and species of extraction solution were investigated with a goal of dissolving all the components except impurites in Olibanum. Meanwhile, supersonic extraction and reflux extraction were compared with a goal of the time to dissolve all the part except impurities, finally, the optimal solution, amount and reflux time were determined. RESULTS All the part except impurities in Olibanum could not be dissolved in only one solution. The method for determining the essential oils and impurities was as follow: a certain amount of Olibanum were extracted with water by steam distillation to obtain essential oils, filter, then the residue were refluxed with 1.25 times actone for 5 min, filter, and the residue were impurites. The content ranges of essential oil in eleven batches of Olibanum were from 1.25% to 4.24%, and those of impurities were from 0.75% to 2.4%. The contents of essential oil in Olibanum were higher than that in processed products, and there was no obvious difference in the contents of impurities. CONCLUSION A method was established to simultaneously determine the contents of essential oils and impurities both in Olibanum and their processed products, and a reference was provided for the establishment of quality standard.