The objective of this study is to explain the evolution of inequality of consumption expenditures of households in Cameroon over the period 1996-2007. To achieve this, we use the Shapley-Shorrocks decomposition of inequality by subgroups and by sources of income / expenses. The application of this method to data from Cameroon shows that expenditure on food and housing explains inequality by sources, while the expenditure distribution is much more unequal in households' headed by a man in urban area and slice aged between 31 and 50 regarding the decomposition subgroup.