The practical determination of the potential river bank erosion requires information on the stream flow conditions, soild compositions of the banks, and the erosion rate of the soild exposed to the flow. Experiments were conducted to measure directly the soil erosion rate (SER) of soil samples extracted from boreholes using an automated version of the LeFeuvre Apparatus (LeFeuvre, 1965; LeFeuvre et al., 1970). The design and operation of the apparatus for the automatic measurement of the SER of cohesive and non-cohesive soil samples is presented. Direct measurements of the wall shear stress and the SER were used to establish the SER-vs-shear stress relationship for the soils analyzed and the corresponding critical shear stresses. The linear model was found to fit best the experimental results.