Flower fragrance is a significant ornamental feature of ornamental plants. Rhododendron is a world-famous woody flower. Rhododendron is famous for its rich colors and diverse patterns, and its fragrance is an important indicator of its quality. Research has demonstrated that the floral compounds of Rhododendron consist predominantly of terpenoids, alcohols, esters, and ketones. Their release is influenced by the flower's development state, release site, and environmental conditions. The analysis shows that terpenoids are the most important floral components of Rhododendron. Terpenoid synthase gene is the main regulatory gene in the metabolic pathway of floral substances in Rhododendron. Genome and metabolomics study found that the TPS family genes of R. ovatum were far more than those of other odorless Rhododendron plants. It is of great significance to study the floral composition and its biosynthesis pathway in different species and varieties of Rhododendron for aromatic breeding and comprehensive utilization. In this study, the determination and analysis methods of floral composition of Rhododendron plants, the aroma components of Rhododendron resources of different subgenera, the synthesis and release law of aroma, and the biosynthetic pathway of aroma and key genes were comprehensively discussed, which provided reference for the study of the genetic law of the synthesis and metabolism of main floral substances in Rhododendron and breeding new varieties with obvious characteristic fragrance.