Data warehouse is a consolidate information repository that provides online analytical processing tools for the interactive data analysis and exploration. Decision-makers could explore the data warehouse with different dimensions and appropriate concept hierarchies to report results they require. However, for library actual practices, the current general ways to produce reports are to query related tables of library automation systems by appropriate designed SQL commands based on their own professional works. It is time-consuming and inflexible. Therefore, the purpose of this study attempts to develop data warehouse applicable to library applications. We analyzed the reports requirements of Taiwan public city and university libraries and then design the fact tables and dimension tables of corresponding data warehouse. We implemented such data warehouse from data of some public library automation system. The results show that applying data warehouse to generate reports of libraries is feasible and efficient.