AIM: To optimize the extraction of the anthraquinone aglycnes from Rhubarb using supercritical fluid extraction(SFE). METHODS: Orthogonal design and variance analysis were used to optimize five operational variables of SFE. RESULTS: The optimized operational variables of SFE were obtained as following: the temperature was 70 ?C , the pressure was 35 MPa, the static extraction time was 8 min, the dynamic extraction volume 5 mL and methanol were used as modifier. CONCLUSION: SFE is rapid, convenient and accurate, and can be used to extract athraquinone aglycones from Rhubarb.