This study was conducted to investigate the dynamic changes of several hormones in Rhododendron simsii floral organs to provide theoretical basis for controlling its flowering period.A R.simsii variety “ Purple Crane” was selected as the experimental material,and its flower organs were sampled at nine floral developmental stages to measure the contents of gibberellic acid-3( GA_3),abscisic acid( ABA),indole-3-acetic acid( IAA),and zeatin riboside( ZR) through enzyme-linked immunosorbent assay( ELISA).The results showed that the content of ZR was highest at full flowering stage; IAA and GA_3 contents were higher than other stages in the process of flower bud differentiation and flowering.ABA played an important role in the regulation of flower bud formation.The results will provide theoretical references for exploring the regulation of plant hormones towards Rhododendron flower traits and breeding new varieties. This study was conducted to investigate the dynamic changes of several hormones in Rhododendron simsii floral organs to provide theoretical basis for controlling its flowering period. A. R.simsii variety “Purple Crane ” was selected as the experimental material, and its flower organs were The results were as follows: sampled at nine floral developmental stages to measure the contents of gibberellic acid-3 (GA_3), abscisic acid (ABA), indole-3-acetic acid (IAA), and zeatin riboside (ZR) . The results showed that the content of ZR was highest at full flowering stage; IAA and GA_3 contents were higher than other stages in the process of flower bud differentiation and flowering. ABA played an important role in the regulation of flower bud formation. Results will provide theoretical references for exploring the regulation of plant hormones towards Rhododendron flower traits and breeding new varieties.