This study uses the contingent valuation method (CVM) to estimate the economic value of planning the three Northern Islets Marine National Park in Taiwan, including option value (OV), existence value (EV) and bequest value (BV). In order to solve problems of high rates of ”zero” response and protest response of the willingness to pay for respondents, Heckman (1979) sample selection model is used to correct selective biases and address the protest response.The empirical results show that respondents with higher WTP are male, college education level or higher, higher income level, and agree with ”establishing three islets marine National park will increase employment opportunities and income for the residents nearby the coast”. Those who often engage in outdoor activities or have been the members of any environmental conservation organization or group, also have higher WTP. In addition, the respondents have higher WTP always with support attitude to ”the establishment of three islets marine National park” or consider to ”designate the area as conservation for lifetime or future generations use” is important. The estimation of average WTP per person for ”option value”, ”existence value” and ”bequest value” is NT$1,420.3, $1,296.78 and $1169.17 per year, respectively.