Plant Transcription Factor Database (PlantTFDB) provides a resource of plant transcription factors (TFs), regulatory elements and interactions between them. In the latest version, It contains 320 370 TFs, classified into 58 families, from 165 species. Abundant functional and evolutionary annotations (e.g., GO, functional description, binding motifs, cis-element, regulation, references, orthologous groups and phylogenetic tree, etc.) are provided for identified TFs. In addition, multiple online tools are set up for TF identification, regulation prediction and functional enrichment analyses.