Abstract: The volatile oil is extracted from zanthoxylum bungeanum maxin using steam distillation. More than sixty kinds of peaks and fifty-two species of compounds are separated and identified by GC/MS. The relative components of these coumpounds are calculated using square peaks to normalization. Among the fifty-two species of identified compounds, there are the eighteen species of hydrocarbon compounds which are mainly caryophyllene (8.44% counted in the eighteen species of identified components)and germacreneand (2.99%) etc, and the thirty-four species of oxygenated hydrocarbon derivatives which are mainly γ-terpineol(10.3%), β-terpineol (9.37%), carveol (8.78%) and caryophyllene oxide (4.23%) etc.