Abstract: This study was conducted from December 11, 2018 to April 15, 2019. A total of 250 apex buds were sampled. The morphological characteristics of buds of Damascus rose at different periods were observed by paraffin section. The statistical results showed that the differentiation of rose bud in Damascus began at the end of January, and completed from the end of march to the beginning of April, lasting about 2 months. The flower bud differentiation can be divided into six stages, namely, the cone differentiation stage of reproductive growth, sepal primordial differentiation stage, petal primordial differentiation stage, stamen primordial differentiation stage, pistil primordial differentiation stage and differentiation completion stage. Flower buds began to differentiate at 5 ℃, the differentiation rate was accelerated at 10~15 ℃, and the differentiation was completed at 15~20 ℃.

Key words: Rosa damascene Mill., flower bud differentiation, morphological characteristics