Abstract:The basic/helix-loop-helix (bHLH) transcription factors play important roles in various developmental processes of eukaryotes. They constitute a superfamily of transcription factors that have been well characterized in mammalian systems, in which considerable structural, functional, and phylogenetic analyses have been performed. The family has been not only implicated in plant growth and developmental processes, including formation of trichome, photomorphogenesis and light signal transduction, but also involved in stress responses and secondary metabolism. The progress of the basic structure and biological function of plant bHLH transcription factors was reviewed.