Background & Objectives : In recent years, the World Health Organization has paid more attention to the relationship between health and social conditions as determining the factors affecting people's health in the society. Social health factors (conditions in which people are born, grow up, work, and become old, and also the health system available for them) have caused inequalities in health and require more attention in health development. The purpose of this research was to identify the determining social and economic factors which are effective in mortality in these selected countries during 1998-2009. Methods: Countries were divided into 3 groups based on the human development index and 10 countries out of each group were studied randomly. The dependent variable in this research was overall mortality and the explanatory variables were Gini coefficient, unemployment rate, per capita Health expenditure, and also the result of multiplication of per capita income and Gini coefficient. To evaluate and assess the data, the generalized method of moment by Eviews 6 was used. Results: The findings showed that the most determining elements affecting the mortality rate in countries with a very high human development index were Gini coefficient (0.02), unemployment rate (0.0001), and the variable obtained by multiplying the Gini coefficient by per capita income (-8.1*10-6). In countries with a high human development index, the most determining elements affecting the mortality rate were unemployment rate (0.005), per capita expenditure (-0.0002), and the variable obtained by multiplying Gini coefficient by per capita income (-3.22*10-6). Also, in countries with a medium human development index, the most determining elements affecting the mortality rate were per capita expenditure (-0.0008), and multiplication of Gini coefficient and per capita income (1.47*10-6). Conclusion: It can be concluded that based on the level of development of the countries, various economic and social factors can affect the mortality and health level of those countries. Therefore, it is necessary for the countries to plan for their health system if they wish to eradicate or reduce inequalities and injustices. This plan should be based on their level of development, the factors determining mortality, and the health system of those countries.