This study aims to examine the mediating effect of ambivalence over emotional expressiveness on the relationship between gender role stress and subjective well-being among middle-aged men, and to explore whether this mediating effect is moderated by generativity. An online self-report survey was conducted with 480 married middle-aged men aged 40-59 years. Data collected were analyzed using SPSS PROCESS macro 4.2. The results revealed several key findings:. First, ambivalence over emotional expressiveness mediated the relationship between gender role stress and subjective well-being. Second, the impact of ambivalence over emotional expressiveness on subjective well-being varied depending on generativity levels. Third, the mediating effect of ambivalence over emotional expressiveness was contingent upon generativity levels. Specifically, higher levels of generativity among middle-aged men attenuated the maladaptive mediating effect of ambivalence over emotional expressiveness, suggesting a mitigation of the decline in subjective well-being due to gender role stress. The significance of this study lies in providing evidence for developing activities and programs aimed at enhancing generativity as a protective factor for middle-aged men.