Abstract: To study the extraction and analysis of chemical constituents in volatile oil from Chuanminshen violaceum, the volatile oil of from Chuanminshen violaceum was extracted by ultrasonic-assisted extraction method and its chemical composition was analyzed by GC-MS. On the basis of single factor experiments, a polynomial regression model was fitted by means of Box-Behnken design. The optimum extraction conditions were as follows:liquid to solid ratio 8∶1 (m L/g) , ultrasonic power 175 W, and ultrasonic time 28 min. Under the conditions, the extraction yield of volatile oil reached 2.213%±0.042%. A total of 76 compounds were detected in the volatile oil, of which 42 were identified, accounting for 97.37% of the total volatile compounds. This study could provide useful references for the development and exploitation of Chuanminshen violaceum.