Abstract: DaF3H，a key gene of anthocyanin biosynthesis，has been isolated from‘Yzi 006’，a purple yam cultivar riching in anthocyanins. DaF3H（KF561995），full sequence of 1 325 bp，had a open reading frame of 1 089 bp encoding 362 amino acids. The DaF3H protein belonged to soluble protein without signal peptide and transmembrane domain，and localized in cytoplasm. The conserved domain search revealed DaF3H belonged to the 2OG-Fe（Ⅱ）oxygenase superfamily. Comparative and bioinformatic analysis showed DaF3H was highly homologous with F3Hs from other plants，such as Juglans regia and Arabidopsis lyrata ssp. petraea（80%）. Expression analysis indicated DaF3H gene had the highest relative expression level in young leaves and less in functional leaves and stems. Anthocyanins accumulatedtrends and DaF3H gene expression level were closely related in leaves，stems and storage stems of yam. Furthermore，a 502 bp nucleotide promoter sequence of DaF3H has been isolated by adapter PCR method and the cis-regulating element analysis predicted there were many elements regulating the expression level of DaF3H in yam，such as auxin，metal ion，MYB-bZIP-MYC complex and GT-1binding sites for light regulation which was proved by the experiment on leaves treated in dark.

Key words: Dioscorea alata, DaF3H, anthocyanins, promoter cloning, expression analysis