Objective：To extract and separate the volatile oil fromanti-influenza sachets，clarify the optimal extraction conditions，analyze the compositions of its volatile oil，and discover the probable functional mechanism of the clinical effect of anti-influenza sachets.Methods：Extracted，separated and collected the volatile oil from37 anti-influenza sachets by stea mdistillation.Multi factor and multi level study of the soaking time(1，2，3，4 h)，extraction time(1，2，3，4，5 h)，solid-liquid ratio(5，10，20，30 times)and extraction times(1，2，3 times)respectively.Ascertained the high-oil-yield conditions of extraction and separation.Qualitative and semi-quantitative analysis of chemical constituents of volatile oilwas carried out by gas chromatography-mass spectrometry(GC-MS).Results：The optimal extraction conditions of collecting the volatile oil fromanti-influenza sachets was soaking with water of 5-time volume for 1 h and extraction for 3 times，once every 3 hours.The main compositions of volatile oil were asar one(43%)and sesquiter pene(50%).Conclusion：The volatile oil of anti-influenza sachets has good availability together with clear composition，and its functional mechanism of preventing and treating recurrent upper respiratory tract infections in children may be related to asarone and sesquiterpene.