Abstract: Changes of poly phenolics and antioxidative activities in petals during florescence and flower senescence of two tree peony cultivarswere analyzed. The results showed that there were richwith total phenolics, flavonoids and anthocyanin of petal in ‘Luoyanghong’and ‘Huhong’, while content of total phenolics decreased in petal during florescence and flower senescence of peonies. The antioxidative activity in the peroxidation system of polyunsaturated fatty acid from lipoprotein induced by iron and secavenging ridical ability in three radical detective systems was at a high level during florescence and declined rip idly after blooming. Significantly positive correlation existed between content of total phenolics and IC50 of DPPH secavenging ability in both the peony cultivars. Itwas proposed that decrease of content of poly phenolics and antioxidative activity was a main physioglical reason for petal senescence of peonies. Tree peonies flowers from early bloom stage to full opening stage possess the high functional benefit and thuswould be the app rop riate stage in view of the nutritional consideration.

Key words: Paeonia suffruticosa, petal, antioxidative activity, DPPH radical, poly phenolics