Fine sediment is carried in suspension by turbulent flow under steady conditions, provided that similar material is present on the bed. An equation is deduced for the variation with depth of the sediment concentration for two-dimensional flow. It is found necessary to take account of the volume occupied by the sediment, this being particularly important near the bed. The result agrees with recent observations by Vanoni (1946). A velocity distribution obtained by Karman, using a linear variation of shear with depth, is generalized by omitting the infinite velocity gradient condition at the bed and is found to be in good agreement with Vanoni's measurements. A slight difference is found between the mean sediment velocity in the direction of flow and that of the water.