Jasminum sambac (jasmine flower), a world-renowned plant appreciated for its exceptional flower fragrance, is of cultural and economic importance. However, the genetic basis of its fragrance is largely unknown. Here, we present the first de novogenome assembly of J. sambac with 550.12 Mb (scaffold N50 = 40.10 Mb) assembled into 13 pseudochromosomes. Terpene synthase (TPS) genes associated with flower fragrance are considerably amplified in the form of gene clusters through tandem duplications in the genome. Gene clusters within the salicylic acid/benzoic acid/theobromine (SABATH) and benzylalcohol O-acetyltransferase/anthocyanin O-hydroxycinnamoyltransferases/anthranilate N-hydroxycinnamoyl/benzoyltransferase/deacetylvindoline 4-O-acetyltransferase (BAHD) superfamilies were identified to be related to the biosynthesis of phenylpropanoid/benzenoid compounds. Several key genes involved in jasmonate biosynthesis were duplicated, causing an increase in copy numbers. In addition, multi-omics analyses identified various aromatic compounds and many genes involved in fragrance biosynthesis pathways. Furthermore, the roles of JsTPS3 in β-ocimene biosynthesis, as well as JsAOC1 and JsAOS in jasmonic acid biosynthesis, were functionally validated. The genome assembled in this study for J. sambac offers a basic genetic resource for studying floral scent and jasmonate biosynthesis, and provides a foundation for functional genomic research and variety improvements in Jasminum.