The purpose of this study is to analyze the economic effects of telepresence system for public sector relocation. As a Green IT system, the importance of telepresence is being recognized increasingly as a means to replacing a majority of business trips and thereby reducing greenhouse gases emitted in the process. However, there are only a few related researches that analyze the economic effects of telepresence at the moment. This study conducts the cost-benefit analysis of 157 public sectors which are to relocate from 2012 based on the sample case of National Information Society Agency. The results obtained reveals that telepresence would save about 180 billion won and reduce about 580t $CO_2$ emission. This study are expected to provide the academic framework for organizations contemplating the adoption of Green IT system moving forward.