Abstract: Juvenile hormones (JHs) are a group of sesquterpenoids synthesized via the mevalonic acid pathway. This review summarized all enzymes involved in the JH synthesis pathway at the molecular level with the ubiquitous JH Ⅲ in insects as example. Furthermore, it introduced two key enzymes: 3-hydroxy-3-methylglutaryl CoA reductase and juvenile hormone acid methyltransferase in detail. In addition, from the silkworm database (http://silkworm.genomics.org.cn), most genes encoding enzymes in the JH synthesis pathway were predicted. Finally, the regulatory mechanism of JH synthesis was discussed and its research direction predicted.

Key words: Juvenile hormone, synthesis enzyme, neuropeptide, Bombyx mori