The aim of this study is to investigate senior primary school students' life stress, leisure coping strategies toward their mental health; in addition, to examine relationships among these variables. This study applied random stratified sampling method to survey primary school students in Xinzhuang District of New Taipei City. A total of 557 students were surveyed, and 529 of them were effective in analysis (94.97%). Independent T-tests, Pearsons' Correlation analysis, and Multiple Regression were employed in this study. Results of this study reveal that there are statistically significant differences of senior primary school students' sex on mental health. Female students have better mental health comparing to male students. Further, life stress negatively influences mental health. While senior primary students perceive higher life stress, it leads to lower mental health. Yet leisure coping strategies do not influence mental health. Based on study findings, suggestions to parents, instructors, and school administrators to pay attention to senior primary students' life stress, regular behaviors, and emotion counseling. Educational institutions can hold related parent-children forums and lectures to promotion leisure coping strategies to enhance family function toward children's mental health.