Recently, requests for citizens to participate in green space conservation activities have been increasing in Japan. However, the amount of management work done by citizens is not always constant because the number of participants is small sometimes. Therefore, it is important to develop a strategy regarding green space conservation from the viewpoint of labor. Using willingness to work (WTW) is defined as “the number of desired participation days per year”, we determined the relation between the willingness of residents to participate in green space conservation activities and the site characteristics of green spaces in the suburbs. The entire Tsurugashima City in Saitama Prefecture was taken as the survey area, and 10 green spaces including parks, forests and streams were evaluated. We conducted a mail survey on the residents of Tsurugashima City; 721 respondents participated in the survey (valid response rate 18%). From the results of this study, we found a significant difference in WTW between residents that lived within l,000 m of each green spaces and the others. However, the situation was just applicable to only green spaces that were over 1 ha.