Based on the reference genome of the hexaploid sweet potato variety Beauregard， a total of 67 IbCOMT family members were identified. Their physicochemical properties， subcellular localization， gene structure， conserved motifs， phylogeny， collinearity， and promoter cis-acting elements were systematically analyzed. The results showed that the number of amino acids of IbCOMT protein ranged from 192 to 721 aa， the molecular weight ranged from 21.01 kDa to 80.47 kDa， and the theoretical isoelectric point ranged from 5.13 to 9.44.The average coefficient of hydrophilicity of most members was negative， indicating that they were hydrophilic proteins as a whole. Phylogenetic analysis divided the IbCOMT family genes into two subfamilies， with members within the same subfamily showing generally conserved exon-intron organization and motif composition. The results of transcriptome expression analysis showed that IbCOMT58 was highly expressed in the aboveground tissues of sweetpotato， and its expression was significantly up-regulated under salt， ABA and drought stress conditions. The IbCOMT1 promoter fragment was used as a bait for yeast one-hybrid screening， and candidate binding factors such as ERF4， NF-YA10， MADS-box， bHLH81 and eIF5A were obtained. The results of point-to-point verification showed that the above candidate binding factors had strong binding activity with the bait fragment. Through the dual luciferase assay in vivo， it was further confirmed that MADS-box， ERF4 and NF-YA10 can directly bind to the IbCOMT1 promoter and play a transcriptional activation function. This study provides candidate genes and experimental basis for further exploring the function of IbCOMT family and the transcriptional regulation mechanism of IbCOMT1 in sweetpotato.