Over the past years, along with the development of socio-economic conditions, the living standard of Vietnamese households has been markedly improved (Thi, 1990; Van, 2004). An overwhelming majority of the people think their living standards ar e now better than before (Anh&Mai;, 2007). It is from household income has had rising and stable tendency. Ne vertheless, there still exists a quite big difference in the income of rural and urban households, as well as between the richest and poorest households due to the structure of household income.