Open government data can improve transparency, participation, collaboration and awareness of government policy. Importance of open government data is increasing but evaluation of its value is still remained a difficult challenge. Existing research focus on conceptualization of value of open government data rather than quantifying utility of using the data. In this research, we will measure value of open government data by using contingent valuation method. This research conducted survey on various citizens and measure value of users in Seoul regarding Seoul Information Communication Plaza, the open government data platform provided by Seoul city. Survey will measure willingness to pay from each groups including general users, professional users and potential users. Value of open government data is estimated and each user group is compared and analyzed.