Urbanization and industrialization bring better living quality as well as new health challenges to human being. Mental stress has increased substantially along with the speeding pace of modern life. People have to find out effective ways to tackle and relieve mental stress when the high intensive pressure becomes inevitable,one of which is social support. Research has shown that social support is significantly associated with mental pressure and diseases. However, no consensus has yet been reached regarding the nature of this relationship. In this paper,we examine this relationship based on a survey of a group of infertile males by setting up a control group to test hypothesis using logistic regression analysis,suggesting that there is a dynamic interactive relationship among social support,mental stress and diseases. Finally,we develop a PCE model to provide theoretical explanations to this relationship.

Analysis of quantitative and qualitative data from a survey of peasant workers in Beijing shows that social identity of peasant-workers is not homogeneously linear and single-dimensional,but complex and multidimensional characterized by of duality.Communication with urban residents,income comparison with urban residents,annual duration of stay in Beijing,and future identity ownership are among the factors significantly influencing duality of social identity.