It is benefited from Universal Soil Loss Equation (USLE) to determine the measures to be taken against erosion on lands being used for agriculture. Through this equation annual sediment deposition in dams and small dams together with their economic storage life are being estimated. This requires the necessity of determining the soil erodibility factor (K), one of the most important parameter of the equation. Totally 3579 soil samples from 0–20 cm depth were taken from Turkish Great Soil Groups and have been analyzed in the laboratory. According to the erodibility values calculated by means of physical and chemical analyses, it has been found that 333 soil samples very highly, 1418 soil sample highly and 1298 were moderately erodible. When the distribution was evaluated according to the Great Soil Groups, 50 % percent of the samples (333) taken from alluvial soils, 31 % (433) of the samples taken from brown forest soils and 38 % (357) of the samples taken from noncalcerous brown forest soils were highly erodible. As a result, a great portion of the agricultural lands were found to be highly and moderately erodible. The proportion of very slightly and slightly erodible soils was only 14 % of the total number of soil samples.