Based on runoff and sediment yield at plot and small watershed scales by field monitoring of 8 years and 7 years respectively in the black soil region of Northeast China

the characteristics of runoff and sediment yield of the first two rainfall events and those of the rest events were compared

which represented the runoff and sediment yield that was influenced and not influenced by freezing and thawing respectively. Results showed that with the effects of freezing and thawing

the runoff coefficient reduced by 0.07 and 0.03 at plot and small watershed scale respectively. Initial abstraction duration increased by 71.7% at slope scale; while

there was no obvious increase at small watershed scale. Soil loss

soil erodibility and sediment concentration increased significantly at both scales under freezing and thawing

and soil erosion was?more?likely to?occured. When the runoff was small

the sediment amount of the rainfall events with freezing and thawing was smaller than that of the rainfall events without it. Compared to those rainfall events without freezing and thawing

the rainfall events with freezing and thawing led to the runoff reduction. As a result

sediment amount of the rainfall events with freezing and thawing was lower at the same rainfall

while it was higher at the same runoff. Freezing and thawing had a more evident effect on rill development and sediment amount at plot scale when runoff was small

as well as capacity of the loose deposits transportation and sediment amount at small watershed scale when runoff was large. The results provide a scientific basis for the quantitative evaluation and transformation model of soil erosion with freezing and thawing in the black soil region of Northeast China.