Abstract: The physiological and biochemical response of Michelia champaca flowers during the process of flower opening and fading. The petals of M. Champaca at different developmental stages were used as materials to observe the changes of morphological characteristics and determine the indexes of dismutase (SOD) activity, peroxidase (POD) activity and soluble protein content.The results showed that the average vase life of M. champaca cut shoots was 8.5 days. The activity of superoxide dismutase (SOD) in petals increased first and then declined during flower opening and fading, and reached highest at full blossom stage. The activity of peroxidase (POD) increased with flowering and fading. Soluble protein content in petal gradually rose at the beginning of flowering, and then rapidly declined after petal colour changing stage. The decreasing of activity of antioxidant enzymes in petal tissue might be the causal factor of senescence of M. champaca flowers.