利用乙醇/(NH4)2SO4在水溶液中形成的分相体系作为多糖提取试剂，采用响应曲面结合BBD中心组合实验试验设计软件，选择优化多糖提取率与响应因素之间的最佳提取模型参数；以琼脂法结合滤纸片扩散半径作为抑菌活性考察指标；采用硫酸亚铁-过氧化氢-水杨酸氧化法和邻苯三酚（焦性没食子酸）自焦性没食子酸自氧化化法考察红景天多糖对活性自由基的清除能力。实验试验结果表明，在最佳提取条件下（1:22.5(g:mL)，50℃，37.5min），红景天多糖提取率16.64%；抑菌实验试验结果表明，红景天多糖对金黄色葡萄球菌的抑菌直径21.1±0.09mm，属于抑菌极敏感型，对大肠杆菌的抑制直径16.4±0.02 mm，属于抑菌高敏感度型，对枯草芽孢杆菌的抑菌直径为12.6±0.04 mm，属于抑制中度敏感型；红景天多糖对三种菌的抑制作用说明，多糖具有一定的抑制细菌活性，且对于不同的菌种的抑制作用具有特异选择性。抗氧化活性研究结果表明，红景天多糖具有清除自由基的能力，参考维生素C阳性对照组的清除率，红景天多糖对羟基自由基（·OH）·OH及过氧负离子自由基（O22-·）O2-·的相对清除率分别为65.1%和51.2%，对应的极限浓度分别为2.0 mg/mL和2.5 mg/mL。以上实验试验结果说明，通过响应曲面优化结合BBD实验试验设计，能够确定红景天多糖提取因素与提取率之间的二次函数模型，为多糖的人工提取提供了定性与定量评价指标；同时红景天的体外抑菌抗氧化活性结果表明，开发具有抑菌抗氧化活性的食品及药品防腐剂具有一定的实际应用价值，为红景植物资源的合理配置及相关产品的多元化应用提供技术指导与实验试验数据参考。

An extraction procedure and method of Rhodiola roseame polysaccharides (RP)and its antibacterial and antioxidant activity evaluation was established by response surface methodology(RSM) and BBD central componse design coupling aqueous two phase system was used to optimize the optimal extraction model parameter between extraction factors and yields of RP polysaccharide. The inhibition zone which used to estimate the antibacterial activities were determined by filter paper diffusion method and  agarophyte method. The scavenging effect to the hydroxyl radical and superoxide radical were detected with the oxidation of ferrous sulfate-salicylic acid- hydrogen peroxide and self-oxidation of pyrogallic acid system. The optimum extraction conditions were found to be extraction temperature 50℃, extraction time 37.5 min and ration of Liquid to materials 22.5 g/mL. Under these conditions, the extraction efficiency of RP polysaccharides achieve 16.64%. The result of antibacterial  activity indicatethat RP polysaccharides present extremely sensitive to staphyLococcus aureus with inhibition diameter of 21.1±0.09mm) and high Sensitivity tocolibacilluswith inhibition diameter of 16.4±0.02 mm, while present moderately sensitive to baciLLus subtiLiswith inhibition diameter of 12.6±0.04 mm.The rusult showed that RP polysaccharides possess a certain antimicrobial activity in vitro and have certain specific selectivity. The evaluation of antioxidant activity suggested that the RP polysaccharides exhibited significant antioxidant activity taking the vitaminC as the reference and obtain maximum scavenging activity of 65.1%(2.0 mg/mL) and 51.2%(2.5 mg/mL) respectively. The quadratic multinomial regression mode between extraction factors and yield was established and be used as the index of evaluating the qualitative and quantitative of extraction method by response surface methodology[1]andBBD design. The result showed that RP possess a certain antioxidant and antimicrobial activity in vitro and has application value for developing as natural antioxidant and antiseptic substance in food and pharmaceuticals industries, while to provide technical guidance and experimental data for Rhodiola roseame plant resources rational allocation and related products diversified application.