Impact of Social Support Networks on Physical and Mental Conditions of China’s Urban Poverty-stricken Population He Zhaiping （Tianjin Norman University，Tianjin，300387） ABSTRACT：By analyzing the random sample of the urban poverty-stricken population in Tianjin，The paper explores the quantity, quality of social support and structure of social support networks on physical and mental conditions of the poor. It proves that the quantity of social support have no efforts on physical and mental conditions of the poor in Tianjin. Quality of social support is positively related to life satisfaction and physical health. the higher The heterogeneity of social support network and the lower network homophily ，the higher the life satisfaction. These indicators have no efforts on physical health. But the more the number of network members whose income level is higher than the ego in whole networks，the worse physical and mental condition of the poor. Keyword：urban poverty-stricken population，social support networks，physical and mental condition