In order to clarify the effect of transverse curvature of the body surface on its frictional resistance, flow along the outer surface of a circular cylinder is studied. Applying the modified momentum transfer theory developed previously by the authors, the velocity distribution is found with curvature effect (Fig. 1). Substituting it into the momentum equation, the differential equation in terms of η1, ratio of the sublayer and the boundary layer thicknesses, position-and radius-Reynolds numbers is obtained. After numerical integration, the frictional resistance is calculated in network of the two Reynolds numbers. The results, compared with the experimental data of Hughes, are shown in Figs. 3 and 4. It is interesting that the good agreement between the theoretical and the experimental results can be got in this old fashioned, as it were, mixture length theory.