For vulnerability reduction of cities to earthquake hazard, such as Tehran city, it is necessary to adopt policies based on the accurate recognition of the nature and causes of vulnerability. The excessiveness of non resistant buildings in developing countries and cities such as Tehran, vaises the question that: Why the degree of seismic vulnerability of buildings, especially residential buildings, is different and high. to answer this question, the review of theories of vulnerability and disaster management showed that retrofitting and vulnerability have deep social dimensions. thus, based on the theories of social structure of vulnerability, the purpose of this research is analyzing the effects of  socio-economic factors on residential vulnerability of houses of Tehran city. The research method is descriptive- analytical. Sample volume of households calculated by Cochran's method (325), and sampling was done by cluster method. Needed data gathered by household and expert questionnaires, and analyzed by correlation and linear regression methods. The findings showed that there are reverse relation between degree of residential vulnerability of houses and income -0.575, literacy -0.692, employment -0.825, socio-economic status -0.665, risk perception -0.326. According to the result of linear regression analysis, 83 percent of changes of seismic vulnerability explained. The Conclusion is that, residential vulnerability and retrofitting have deep socio- economic dimensions. So, for buildings retrofitting, in addition to technical and engineering factors, socio-economic factors such as poverty reduction and socio-economic empowerment of households and individuals must take in attention seriously.