Economic growth and income differentiation problems are the most actual problems of modern research. The research is attributed to sustainable development research area. In a case of Latvian economy these problems have a huge actuality because of lack of researching works, where these parts of science are completely opened. Special interest causes question about the trajectory of economic growth and and uneven income. If GDP growth is connected with increasing income differentiation of population, then increasing income differentiation absorbs part of the effect on the growth of aggregate income. If GDP growth is on the background of lower income differentiation, the increase in total income is supplemented by regularity of revenue growth. Thus the social effect of economic growth increases significantly. What trends are taking place in income differentiation by regions and economic development of the regions in Latvia after the EU accession? What trends are taking place in interregional differentiation in income per household member, and in GDP? Is there a relationship between trajectories of economic growth and income differentiation in the regions of Latvia?