To understand the present status and the development of the digital reference service in Korean public libraries, a nationwide site observation was attempted in 2007. The collected data was analyzed, then compared with the previous analysis based on a 2003 data. For the 404 sites offering digital reference, operational characteristics, such as access level, service mode, link description, policy, web form, and FAQ, are analyzed. Performance analysis focused on the presence of question posting, volume of usage, response rate, and types of the questions, for the data collected for 15 days through question and answer transcript recording. Results reveal findings on the present situation as well as changes over 4 years.Related problems are identified. The conclusion includes suggestions for improving digital reference service.