Introduction and purpose:Depression is effect by several psychological factors, that from most

important can be note social support and loneliness noted.  Therefore this research aimed to predict depression based on the mediating role of social support loneliness among the elderly.

Materials and Methods:  This is a descriptive study of correlational type. The statistical population of this research included all elderly of  Khorramabad  City in 2016 year that from them 100 elders was selected by convenience sampling method. Data collection tools included the questionnaires Beck Depression ( 1961), Social Support (wax & et al, 1986), loneliness Russell (1966) that were completed by samples. Data was analyzed by using the SPSS-24 software and correlation and multiple regressions with enter model methods.

Findings: The results indicated that: the subscales of family support and friend support negatively predict depression. The subscales of social support, negatively predict loneliness.

Conclusion: According to the findings of this research social support  mediated by loneliness can affect depression. Therefore, the role of these variables in predicting depression, the results can provide useful information to reduce depression and loneliness in old people's families.