Abstract: CaCO3 distribution of the loess plateau was studied by use of EDX(EDS).The results showed that much CaCO3 was distributed among loess and its aggregates.The quantity of large particle CaCO3 was small,and the CaCO3 was distributed among mineral particles with incrustation style.The quantity of small particle CaCO3 was large,and these CaCO3 were distributed mainly over mineral particle surface with adsorption style.EDX was not only used to determine main composition(including CaCO3) of loess,but also could show its distribution.The way of discussing the CaCO3 distribution by Si,Al,Ca overlap distribution picture of loess was feasible.