Living arrangement has been documented to be influential on older adults’ health. However, there is hardly comprehensive temporal model for understanding the effects of time and cohort on oldest old’s health in various household contexts. This study intended to fill the voids of prior literature by studying Chinese oldest old through analyzing data from eight (1998, 2000, 2002, 2005, 2008, 2011-12, 2014 and 2018) waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The results showed changing patterns of Chinese oldest old’s living arrangements by time period and across birth cohorts. Chinese oldest old were more inclined to live with a spouse or live alone. Living in nursing homes was also chosen by more oldest old in recent years. Younger cohorts were more inclined to live with a spouse, live both with a spouse and adult children/grandchildren or live alone than older birth cohorts. Oldest old who lived with a spouse only, and those living in multigenerational families tended to have better physical and mental health. Respondents who lived in nursing homes and stayed with others showed the worst physical and mental health. Oldest old who lived alone had better physical health but suffered from loneliness and reported the worst subjective wellbeing. Significant period and cohort variations were also found when linking living arrangements to oldest old health. Cohort variations mainly occurred among subgroups living alone, staying in nursing homes and living with others. Period effects were more prominent than cohort effects, especially in times of economic recessions and natural disasters that had massive social impacts. The study emphasized strong period effects and highlighted that special attention should be given to more vulnerable groups to promote their health, including those living alone, living in nursing homes and living with others.