This paper uses data from the online statistical database (2012) of the World Bank and the United Nation Human Development Report (2011) to investigate intra-income distribution in different income-groups countries and to study the relationship and the impact of per capita income over subjective and objective social welfare or well-being. The results from cross countries analysis unearthed that high income countries have higher disparity or inequality among themselves than the low income countries and middle income countries in the world. The per capita income has significantly positive relation and strong impacts on subjective as well as objectives well-being or happiness.