Social support is an important factor in terms of the enhancement of the client and has been acknowledged widely as an effective component of well-being. In spite of the lack of a unanimous definition of social support, the structural and functional aspects of social support can be used as a framework for designing social support. Not only the receiving social supportbut also the giving social support and the reciprocity of social support are important factors of influencing on individuals\' psychological well-being. Also, the effect of social support differs depending on whether it is perceived or actually received. The social support transaction is a dynamic process which connects the structure and the function of social support. Perceived and enacted social support are the dimensions of this social support transaction. There are two kinds of the effects of social support: positive and negative. The positive effects of social support are defined as follows: the main or the direct effect of social support and the moderating effect. Whether social support has a main or moderating effect depends on the types and dimensions of social support. To find a significant effect of social support, especially moderating effect, the methodological issues such as designing, sampling, measurement must be considered.
Keywords: social support receiving, social support giving, structural and functional support, direct and moderating effect, methodological issues.