The characterization of soil erodibility at watershed scales is important from the standpoint of designing best management practices to reduce sediment and chemical loadings of streams. This research was conducted to evaluate a method for assessing erodibility and determine its distribution as a function of soil geomorphology on a watershed scale. Each major soil type in six subwatersheds (SW) was sampled along transects positioned to represent normal soil geomorphological features associated with a given mapping unit. At each sampling point, latitude-longitude, slope gradient, slope position and slope aspect were recorded. Soil samples collected from the surface 5 cm were characterized for particle size distribution, water dispersible clay (WDC), organic and inorganic C, magnetic susceptibility, pH and quantitative soil color. Suspended sediment samples collected from supercritical flumes at the mouth of each SW were characterized for similar parameters. A soil aggregation index (AI) was calculated for each SW as follows: 100 (1-WDC/total clay). Clay contents of the soils and suspended stream sediments, which were used as indicators of susceptibility to erosion, averaged 141.3 and 179.3 g/kg, respectively. Enrichment ratios (ER) for clay contents ranged from 1.03 to 1.67. A correlation coefficient ( r ) of -0.946 (P<0.01) was obtained for AI versus EI indicating that AI can be used to infer watershed soil erodibility on various landscape positions, and the resulting suspended sediment properties.