In this research, it has been tried to review and analyze the role of income inequality in achieving sustainable prosperity in Shiraz metropolis. Some measurement methods of income inequalities in economics are determined and possible ways of distributive factors which influence on welfare dimensions in economics are presented. This research is a quantitative-analytical one and the research territory includes Shiraz metropolis from 2002 to 2006. The segmented data of distributing income-cost for the studied city are according to gathered sub-data of income-cost plan. Finally, using Atkinson’s, Dalton’s, Tile’s and Hirschman’s indices, income inequalities in Shiraz were investigated during the above-mentioned era. Adopting Atkinson’s index and considering inequality sensitivity degrees, the research findings show that the highest level of inequality was in 2005 and 2006 and the lowest level of inequality was in 2002 and 2003. Furthermore, Tile‘s index shows that the highest level of inequality was in 2003 and the lowest level was n 2006; this index has tended toward equality since 2003. Hirschman’s index indicates an unequal trend which was increasing between 2002 and 2003, and decreasing between 2003 and 2004. According to some scholars, including Bakerman (1980), Daly and Cobb (1989), Klasen (1994), Hicks (1997), and Stymne and Jackson (2000), when income inequality increases and there is no distribution of justice, the household welfare will decrease. One may claim that such income inequalities have negatively influenced welfare in Shiraz metropolis.

Key words: Atkinson’s welfare Function; Dalton’s index; Hirschman’s index; Tile’s index; Shiraz metropolis .