Abstract: The volatile components of Toona sinensis leaves was extracted by ultrasonic- assisted extraction method and its chemical composition was analyzed by GC- MS. Based on the single experiment,the extraction yield of volatile components in Toona sinensis leaves as the response value,the best condition of volatile components extraction was optimized by orthogonal array design and analysis. At last,the results showed that ultrasonic time had the greatest impact on the extraction of volatile components,followed by mesh number of Toona sinensis leaves,liquid- solid affected least.The optimum extraction conditions were mesh number of Toona sinensis leaves100 mash,ultrasonic time 20 min,and liquid- solid ratio 1∶30( g ∶ m L).Under this condition,the average value of the experiment was 6.42%. Totally 73 compounds were identified by GC- MS,accounting for 66.95% of the total separated volatile compounds. The major compounds identified were ester,thiophenes,while terpenes and long chain alkane.