Abstract: In order to understand the effect of granular structure on the forming process of soil crust, soil splash erosion rate was measured and soil slice was made through artificial simulated rainfall splash erosion test, the effect of different diameter granular structure on loessal soil splash erosion rate and crust formation was analyzed. The results showed that the soil with diameter of 0.15 mm≤D＜2.0 mm and D＜0.038 mm formed crust easily, when the duration of rainfall was 5 min, soil surface formed crust and the crust tended to be complete as rain continues; while soils granule with medium diameter aggregates (0.038 mm≤D＜0.15 mm) was more difficult to form crust, when the duration of rainfall was 5 min, there was no curst developed. When the soils granule diameter was 0.105 mm≤D＜0.22 mm, the soil splash erosion rate increased with the decrease of diameter, the soil splash erosion rate reached the highest with the diameter of 0.096-0.15 mm, then, the soil splash erosion rate gradually decreased with the decreased of diameter.