Extraction of steam distillation for WU-du Zanthoxylum bungeanum( cv. Dahongpao) essential oil was optimized by single factors analysis and central composite design( CCD). The results indicated that the optimistic parameters of essential oil extraction were : the material-water ratio 0. 11( m /v),the vapor volume 73 mL and the distillation time 96 min. Under these conditions the extraction yield of essential oil was 6. 71%. Essential oil from the optimum technology was analyzed by gas chromatography-mass spectrometry( GC-MS). Seventy-three volatile components were separated,and 31 of them were identified,accounting for 95. 16% of the total volatile components. The main ingredients for the fragrance were limonene 20. 204%,linalool 16. 645% and linalyl anthranilate 19. 733%,and the relative content of linalyl anthranilate was higher in WU-du Zanthoxylum bungeanum( cv. Dahongpao).