Objective  To estimate the prevalence of frailty and to explore risk factors of frailty among elderly people in endowment institutions in Nanjing city for providing evidences for establishing intervention programs.

  Methods  A cross-sectional study was conducted among 479 persons aged 60 years and older selected with cluster sampling combined with purposive sampling in 14 endowment institutions in Nanjing city during July 2015. The influence factors of frailty were analyzed with binary logistic regression model.

  Results  Among the participants, 147 were identified with frailty and the prevalence of frailty were 30.7%; the proportions of main frailty problems were 79.7% for grip weakness, 72.9% for slow walking speed, 24.2% for low physical activity level, 15.7% for perceived fatigue, and 7.1% for reduction in body weight, respectively. The results of multivariate logistic regression analyses showed that the risk factors for frailty among the participants were with a general self-rated health status (odds ratio OR = 1.918, 95% confidence interval 95% CI: 1.152 – 3.193) and a poor self-rated health (OR = 3.021, 95% CI: 1.561 – 5.846), with a slightly impaired activity of daily life (OR = 2.433, 95% CI: 1.301 – 4.550), with a moderately or severely impaired activity of daily life (OR = 6.051, 95% CI: 1.401 – 30.171), and with a severely impaired social participation (OR = 2.596, 95% CI: 1.525 – 4.419).

  Conclusion  The prevalence of frailty is high and associated mainly with poor self-rated health and impaired activity of daily life and social participation among the elderly people living in endowment institutions in Nanjing city.