Abstract: In order to explore the extracting effect of antioxidants from Terminalia chebula Retz(TCR) based on ultrasound assisted extraction with constant temperature technology(UAECTT),at first,the extraction technology of antioxidants were optimized,then the reasons for high efficiency of this extraction technology were analysized by comparative experiments and scanning electron microscope(SEM). The optimal parameters of the extracting technology were as follows the concentration of ethanol 60%,the ultrasound frequency 80 k Hz,the ultrasound power 180 W,and the extracting temperature 70 ℃. The extraction efficiency of UAECTT dramaticlly was higher than that of water bath oscillator extraction(WBOE)(p<0.001) based on the comparative analysis. A comparison of SEM images of TCR powders indicated the extraction efficiency was higher treated by UAECTT with the more serious disruption of cell structure and the more sufficient interaction. The technology of UAECTT was proved as one technology with high efficiency for extracting TCR antioxidants and this study provided the basis for future industrializing development of TCR.