Abstract: Respiration rates and endogenous hormone levels were measured during florescence and senescence of Paeonia suffruticosa cultivars‘Luoyanghong’and‘Huhong’. The results showed that respiration rates of‘Luoyanghong’and‘Huhong’were characterized by a typical climacteric，exhibiting a peak of respiration rate at full-opening and middle-opening stage，respectively. It was found that a decline in the content of soluble proteins but an increase in anthocyanin in peony petals after opening. The contents of endogenous IAA，ZR and GA3 decreased，however，endogenous ABA accumulated in petal of peony during florescence and senescence. The change pattern of ethylene production in‘Luoyanghong’was like that of ethylene climacteric cut flower，while the change pattern of ethylene emission in‘Huhong’was like increase during later stage. The data suggest that senescence of peony petal can be attributed to metabolic unbalance of endogenous hormone levels during florescence and senescence.

Key words: Paeonia suffruticosa, florescence and flower senescence, respiration climacteric, endogenous hormone