The biostratigraphic comparison and sedimentological features of the Maokou limestone in SW China demonstrate that differential erosion and crustal uplift were developed prior to eruption of the Emeishan flood basalts. Four sedimentary zones are distinguished with the erosional degree decreasing from west to east. The erosion scope is coeval with the spatial distribution of the Emeishan basalts. It is suggested that differential erosion is caused by a rapid crustal uplift or doming related to the mantle plume activity. This paper discusses the spatial distribution of the Emeishan Large Igneous Province on the basis of the upwelling mantle plume-crustal uplift model and estimates the scale of Emeishan LIP.