The Trihelix transcription factor family has raised great concerns only in recent years. It was named after its conserved DNA binding domain containing three tandem helix (helix-loop-helix-loop-helix), which could bind specifically with GT element, a light-responsive DNA element. So, this family is also known as GT factors. At the early stage of study, the knowledge of this family was only confined to their functions in regulation of light-responsive genes. However, recent researches indicated that Trihelix family also plays important roles in different growth and development processes involving flowers, stomata, trichomes, embryos, and seeds, as well as roles in response to abiotic and biotic stresses. This review mainly focused on the structural characteristics, classification, and the latest functional research progresses on the Trihelix family.