Abstract: Arabinogalactan in residual products of Larix gmelinii Rupr.wood was extracted with the assist of ultrasonic wave.The extraction condition that influences the yield of arabinogalactan was studied,including ultrasonic wave (power),mass ratio of liquid to material,raw material granularity and extraction time.The results of ultrasonic extraction were compared with those of traditional extraction and microwave extraction.The extracts were analyzed by infrared spectrogram and ultraviolet spectrogram.UV absorbance of impurities in extract from ultrasonic extraction at 280 nm is the lowest;the quality is close to the standard of pure arabinogalactan.In single factor experiment, the highest extraction yield of ultrasonic extraction is 16.61%,which is higher than traditional extraction.