This research presents the role of the epmloyee's mental health self-management activities in maintaining psychological wellbeing among industrial workers. A questionnaire survey was conducted for 197 workers at the manufacturing company in Nagoya. The respondents' average age was 38.6, and the mean years with the company were 17.7. In this questionnaire, each employee was asked to respond to the following three measures: job stressor, mental health self-management activities, and strain measures. The aim of this research is to examine two hypothesis; 1) There will be a direct effect of mental health self-management activities upon the measure of strain; 2) The moderating effect of the mental health selfmanagement activities will work to buffer the negative impect of the stressor upon the psychological wellbeing of the respondents. The result showed that the direct effect of the mental health self-management activities upon the strain measures was significant. However, despite the seeming interaction pattern between job stressor and mental health selfmanagement upon the strain variables, the result failed to show the statistically significant result. Thus, the second hypothesis was not supported.