Abstract: Abstract:As a key index in evaluating consumption level of inhabitants, Engle＇s coefficient plays an important role in the measurement of inhabitant＇s living standard. Due to the influences of restraint of traditional consumption behavior, rapidly rising expense of education, housing and medical treatment, revenue level, the limitation of statistical method and increasing disparity of the rich and the poor, Engle＇s coefficient of urban residents shows some characteristics in the underdevelopment counties.

Key words: Key words:Engle＇s coefficient, Particularity, Expenditure on foodstuff