OBJECTIVE： To optimize the extraction technology of total flavonoids from the root， stem and leaves of Alpinia galangal and compare the antioxidant activities of the flavonoids in vitro. METHODS： Taking into account the four factors， such as the ratio of solid to liquid， the volume fraction of ethanol， the temperature of enzymatic hydrolysis and the time of ultrasonic， using the extraction rate of total flavonoids as index， with the method of ultrasonic assisted， the extraction technology of total flavonoids from A. galangal was optimized by Box-Behnken response surface test on the basis of single factor experiment. The antioxidant activity tests in vitro of different concentrations of total flavonoids （0.1-1.0 mg/ml） from different parts of A. galangal were conducted， including DPPH free radical clearance test， O2－ free radical clearance test， protective test of vegetable and animal fat [using vitamin C （VC） as control]. RESULTS： The optimal extraction technology as follows as the ratio of solid to liquid was 1 ∶ 23.8； the volume fraction of ethanol was 60％； water bath temperature was 80 ℃； ultrasonic time was 33.5 min. Under this condition， the extraction rates of total flavonoids from the root， stem and leaves of A. galangal were 53.5， 52.7， 52.5 mg/g. The rates of their relative error from predicted value were all no more than 2.48％. When the mass concentration was 0.5 mg/ml， the antioxidant capacity of total flavonoids from different parts of A. galangal to DPPH free radicals was as follows as leaves （94.3％）＞root （93.6％）＞stem （90.8％）； the antioxidant capacity of VC was 96.4％. When the mass concentration was 1.0 mg/ml， the antioxidant capacity to O2－ free radicals was as follows as root （63.7％）＞stem （60.2％）＞leaves （42.9％）； the antioxidant capacity of VC was 94.7％. When the mass concentration was 0.4 mg/ml， the protective rate to vegetable fat was as follows as leaves （39.7％）＞stem （30.6％）＞root （28.3％）； the protective rate to animal fat was as follows as leaves （40.6％）＞stem （30.2％）＞root （29.3％）； the protective rate of VC was about 60％. CONCLUSIONS： Optimized extraction technology is feasible， and can be used for the extraction of total flavones from different parts of A. galangal. Total flavones from different parts have certain antioxidant activity， specially the total flavones from leaves of A. galangal is stronger than other.