PCMDB contains three different types of cell markers for six model plants (Arabidopsis, rice, maize, soybean, tomato and tobacco), including experimentally validated marker genes, differentially expressed marker genes based on transcriptomic data, and differentially expressed genes across specific cells identified by single cell RNA sequencing. 3119 experimentally validated marker genes were collected by manually curating over 1676 literatures. Meanwhile, information including tissue type, sub-tissue type and cell type were also recorded. 0 marker genes were identified based on differential expression analysis using bulk RNA-Seq data. Moreover, 0 marker genes were collected from single-cell RNA sequencing studies. PCMDB provides a user-friendly interface for browsing, searching and downloading markers of various cell types from different tissues. Different analysis tools, including cell type prediction and cell marker prediction, are also provided to facilitate different purpose of users.