This paper examines the relationship between Mandarin proficiency and life satisfaction in China using data from the 2017 China General Social Survey. Drawing on the literature on language and well-being, we hypothesize that Mandarin proficiency is positively associated with life satisfaction and that this relationship may be moderated by factors such as gender, region, urban-rural status, and household income. We employed multiple regression analyses to test our hypotheses, controlling for various demographic and socioeconomic variables. The results show a positive and significant relationship between Mandarin proficiency and life satisfaction and support the moderating effects of gender, region, urban-rural status, and household income. Our findings have implications for language policy and suggest that promoting Mandarin proficiency can help improve individuals' life satisfaction and well-being in China.