Objective  To investigate the mediated moderation effect of physical health and mental health on the correlation between social support and subjective well-being in elderly people, and to provide evidences for using social support effectively to improve subjective well-being of the elderly and achieve a positive and healthy aging.

  Methods  With quota sampling, 978 elderly residents aged≥60 years who lived in 7 urban communities of Shenyang, Dalian, Jinzhou, Panjin, Fushun, Benxi, and Tieling municipality of Liaoning province were selected for a questionnaire survey during April to June 2016. With structural equation modeling, product-of-coefficients based bias-corrected percentile bootstrap method was adopted to assess complete mediation effect by introducing auxiliary variables into the model.

  Results  For all the elderly, the average scores of physical health and mental health were 2.96 ± 0.18 and 3.65 ± 0.84; the average score of social support of was 3.31 ± 0.84; and the average score of subjective well-being was 3.84 ± 1.00. Social support showed significant positive impacts on subjective well-being of the elderly (c′ = 0.574, P < 0.05). Significant specific mediation effect (a₁b₁, a₂b₂), total mediation effect (a₁b₁ + a₂b₂), and contrast mediation effect (a₁b₁ – a₂b₂) of physical health and mental health were observed (P < 0.05 for all), with corresponding confidence intervals of 0.003 – 0.020, 0.121 – 0.353, 0.132 – 0.365, and – 0.532 – – 0.129, and a proportion of mediation effect (P_M) of 30% to total effect. Moreover, the mediating effect of mental health was much greater than that of physical health (a₁b₁ – a₂b₂ = – 0.347).

  Conclusion  Social support exerts direct effect on subjective well-being and plays its role partly through the medication of physical health and mental health among the elderly people.