Abstract: The extraction and anti-oxidation activities of total flavonoids from Toona sinensis leaves by enzymaticultrasonic were studied. Cellulase dosage,p H and ultrasonic power were screened out by Plackett-Burman as the significant affected factors. The optimum extraction conditions were established by using 3 factors and 3levels response surface experiment. The result showed that the optimal extraction conditions of total flavonoids were the hydrolysis temperature and ultrasonic extraction temperature of 60 ℃,the solid-to-solvent of 1∶30 g/m L,the ethanol concentration of 70%,ultrasonic extraction time of 40 min,cellulase dosage of 8 mg,p H =5.6,ultrasonic extraction power of 220 W,the extraction rate under this condition reached 33.166 mg/g. The anti-oxidation activity experiments results showed that the IC50 of ·OH and DPPH· scavenging rate were 22.85 μg/m L and 53.74 μg/m L respectively.