Purpose - This paper aims to identify the information needs of users of the National Taiwan University Library and to formulate improvements to the interlibrary loan service by examining the usage statistics of the document delivery systems NDDS and RapidILL. These results may serve as future reference materials for other libraries operating document delivery services. Design/methodology/approach -The study used the technology acceptance model (TAM) to analyze user behaviors and system acceptance levels in the NDDS and JADE document delivery service systems (JADE is the application interface of the RapidILL in National Taiwan University library). Findings – 1.RapidILL performs better than NDDS in the following areas: usefulness, ease of use and system satisfaction. 2.Yields a clearer understanding of users’ needs from statistical analysis.