The damage of the bridge foundations, in the river flow, because of scour leads to considerable economic and environmental losses The equilibrium stage of scour near guide banks with a uniform layer and stratified bed conditions have been studied. At present, no methods are available for computing the depth of a local scour near the bridge crossing structures under river bed layering. The aim of this study is to elucidate the influence uniform bed and stratification on the scour depth at elliptical guide banks for clear water conditions on the plain rivers Scour process is studied according to one of the cases proposed by Ettema (1980), when first layer or next one is fully scoured out. The depth of scour considerably increases or reduces - depending on grain size of uniform layer and sequence, thickness of layers with different grain sizes. For example, the depth of scour is always greater when a fine-sand layer is under a coarse-sand layer(s) compare with the depth of scour obtained in coarse-sand layer with mean grain size, which is on the top of the river bed. A new method for computing the equilibrium scour depth at elliptical guide banks in uniform and stratified river bed conditions is presented. Equilibrium depth of scour can be calculated by proposed formulas in one or several bed layers with different mean grain size, thickness, and sequence combinations. The method is confirmed by test results. Calculation of the depth of scour at the bridge foundations in the flow and taking into account only the grain size diameter in the upper layer of the river bed, as it excepted now, and neglecting stratification will lead to wrong results and finally to considerable damages and losses.