The results of 463 college students were analyzed using the psychological growth environment(PGE) scale, Additionally the way of coping checklist and the subjective happiness(SH) scale, were utilized to investigate the effects of perceived psychological growth environment and stress coping strategies on the happiness of college students. Through correlation analysis, we studied the relationship between psychological growth environment, stress coping strategies, and level of subjective happiness, and examined the differences in each variable according to gender. We analyzed what was most influential on subjective happiness among PGE, sub-factors of stress coping strategy, and gender, and then whether emotional relaxation, which is the most influential factor for SH, mediates the effect of PGE on SH. In the results that examined the correlation between each variables, PGE perceived by college students and coping strategy showed a positive correlation, and PGE and SH also presented a positive correlation. However, stress coping strategy and SH showed a negative correlation, and emotional relaxation and hopeful thoughts were negatively correlated with SH among the sub-factors of stress coping strategy. Second, as a result of verifying the differences in each variable according to gender, male college students reported higher SH than female college students, and female college students reported a higher tendency to seek help and use hopeful thinking among stress coping strategies. Third, emotional relaxation was the most important factor affecting SH among PGE, sub-factors of stress coping strategy, and gender. Fourth, in the relationship between PGE and SH, emotional relaxation had a negative partial mediating effect. Considering the overall results of this study, perceived PGE affects SH, and emotional relaxation in the stress coping strategies has a negative effect on SH.