[Objective] The paper was to understand the physiological response of space flight mutation new strains of Festuca arundinacea to high temperature stress. [Method] The influence of high temperature stress on eco-physiological characteristics of 11 F. arundinacea materials was studied in a pot experiment.Physiological and biochemical indexes,including soluble protein content,superoxide dismutase( SOD),peroxidase( POD) and catalase( CAT) activities,were measured and analyzed once every 4 d for a total of three times. Subordinate function and grey rational analysis were used to comprehensively evaluate the heat resistance of 11 materials. [Result] The soluble protein content decreased with the extension of heat resistance stress,while SOD,POD and CAT activities showed an upward trend. The high temperature resistance of 11 F. arundinacea materials was evaluated by subordinate function method. The resistance order was SP5-85> SP5-60 > SP5-71 > SP5-42 > SP5-94 > SP5-7 > SP5-88 > F. arundinacea cv Shuicheng > SP5-5 > SP5-89 = F. arundinacea cv Qiancao No. 1. The relational order of various heat resistance indexes and heat resistance obtained by grey rational analysis was SOD > CAT > POD > soluble protein content. [Conclusion]The result provides a theoretical basis for stress physiology and stress breeding of cold season grass in southwest region. [Objective] The paper was to understand the physiological response of space flight mutation new of Festuca arundinacea to high temperature stress. [Method] The influence of high temperature stress on eco-physiological characteristics of 11 F. arundinacea materials was studied in a pot experiments. Physiological and biochemical indexes, including soluble protein content, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, were measured and analyzed once every 4 d for a total of three times. were used to comprehensively evaluate the heat resistance of 11 materials. [Result] The soluble protein content decreased with the extension of heat resistance stress, while SOD, POD and CAT activities showed an upward trend. The high temperature resistance of 11 F. arundinacea materials was evaluated by subordinate function method. The resistance order was SP5-85> SP5-60> SP5-71> SP5-42> SP5-94> SP5-7> SP5-88> F. arundinac ea cv Shuicheng> SP5-5> SP5-89 = F. arundinacea cv Qiancao No. 1. The relational order of various heat resistance indexes and heat resistance obtained by gray rational analysis was SOD> CAT> POD> soluble protein content. ] The result provides a theoretical basis for stress physiology and stress breeding of cold season grass in southwest region.