Background: The relationship between socio-economic status and health among elderly people has been well studied, but less is known about how spousal or offspring’s education affects mortality, especially in non-Western countries. We investigated these associations using a large sample of Chinese elderly. Methods: The data came from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from the years 2005 to 2011 (n = 15 355, aged 65–105 years at baseline; 5046 died in 2008, and 2224 died in 2011). Educational attainment, occupational status, and household income per capita were used as indicators of socio-economic status. Spousal and offspring’s education were added into the final models. The Cox proportional hazards model was used to study mortality risk by gender. Results: Adjusted for age, highly educated males and females had, on average, 29% and 37% lower mortality risk, respectively, than those with a lower education. Particularly among men, this effect was observed among those whose children had intermediate education only. A higher household income was also associated with lower mortality risk among the elderly. Male elderly living with a well-educated spouse (HR 0.79; 95% CI, 0.64–0.99) had a lower mortality risk than those living with a low-educated spouse. Conclusions: Both the socio-economic status of the individual and the educational level of a co-resident spouse or child are associated with mortality risk in elderly people. The socio-economic position of family members plays an important role in producing health inequality among elderly people.