Abstract: In order to reveal the particle composition of different salinized soils and its relationship with soil erodibility K value in Delingha City of Qinghai Province, the EPIC model based on the mechanical composition and organic carbon volume content was used to estimate the soil erodibility K value, the soil particle size distribution, erodibility K value and their relationship of five kinds of salinized soils in this area were analyzed. The results showed that: on the whole, the soil particles in Delingha City were mainly composed of powder particle (55 % -84 %) and sand grain (15 % -44 %). With the increase of salinization degree, the soil texture gradually became finer. The K value of erodibility factor was ranged from 0.048 to 0.061, with an average value of 0.054. According to the classification standard of soil erodibility K value, the soil in the study area belonged to the soil with high erodibility (K＞0.048), and there was a high risk of erosion. By analyzing the correlation between the K value of soil surface erodibility and the composition of 8 soil particle sizes, it was found that the K value of erodibility factor was significantly positively correlated with clay particle and powder particle (P＜0.01). It showed that the salinization of surface soil in Delingha City was serious, and the increase of fine particles made the erodibility factor K value increase, and the soil was more susceptible to erosion