In Plant Circular RNA Database (PlantcircBase), we collected publicly available back-splice junction sequences and their full-length sequences of circRNAs identified in plants by us and other groups. Based on the collected circRNAs, we further predicted those circRNAs putatively acting as miRNA sponges and their potential networks involving circRNA-miRNA-mRNA in the corresponding species.In the database, you can find plant circRNAs and their related information, such as their sequences, host genes, expression, experimental validation as well as bioinformatics tools for visualizing circRNA structures and predicting circRNAs from query sequences.