An individual's happiness is closely related to their family life as the family is the institution in which they spend most of their life. Capitalizing on data from the 2018 China Family Panel Studies, this study investigates the relationship between family economic standing (measured by household income and homeownership) and family processes (measured by marital status and childlessness), as well as children's characteristics (measured by gender composition of children and adult children's educational attainment and marital status), and happiness of Chinese adults. We take a life-course perspective and examine how such relationships vary across different life stages. We find that factors like household income and homeownership are positively related to happiness for people in general; that married adults are happier than those who are unmarried; childlessness results in decreased individual happiness in old age; adult children's educational attainment, measured by college degree (three-year and four-year) and above, improves parents’ happiness; while children's unmarried status makes parents less happy. These significant relationships also change across the life span.