In prokaryotes, the xcfx8354 promoters are unique regulatory elements and have attracted much attention because they are in charge of the transcription of carbon and nitrogen-related genes and participate in numerous ancillary processes and environmental responses. All findings on xcfx8354 promoters are favorable for a better understanding of their regulatory mechanisms in gene transcription and an accurate discovery of genes missed by the wet experimental evidences. In order to provide an up-to-date, interactive and extensible database for xcfx8354 promoter, a free and easy accessed database called Pro54DB (xcfx8354 promoter database) was built to collect information of xcfx8354 promoter. In the current version, it has stored 210 experimental-confirmed xcfx8354 promoters with 297 regulated genes in 43 species manually extracted from 133 publications, which is helpful for researchers in fields of bioinformatics and molecular biology.