Abstract: The cut flowers of Freesia hybrida‘Shangnong Jinhuanghou’were used as materials to study their phenotype changes and their physiologic response during vase holding. The results showed the vase life of an individual flower and a whole inflorescence was less than one week and 10 days，respectively. The contents of natural water and soluble protein in the petals increased at the early stage of vase holding，and then decreased 4 days later. The activities of superoxide dismutase（SOD），catalase（CAT）and ascorbate peroxidase（APX）increased in preceding stage，and decreased rapidly in later stage. However，the activity of peroxidase（POD）increased with the time postponing of vase holding. The content of superoxide radical（）was accumulated during vase holding. Meanwhile，the malondialdehyde（MDA）content and the electrolyte leakage increased with the process of vase holding. The water loss，the decrease of activities of antioxidant enzymes and the accumulation of  and rising of lipid peroxidation level were considered to be the main physiological causes of senescence of cut Freesia flowers.

Key words: Freesia, cut flower, reactive oxygen species（ROS）, antioxidant enzymes, membrane system, senescence