Ephemeral gully erosion in cultivated land is an important source of sediment.Topography has significant impacts on its development.The correlation between catchment topography and ephemeral gully erosion in northeastern China with black soils was discussed.The results show that ephemeral gully length and eroded volumes are significantly correlated with watershed length.A critical slope-upslope area relationship(S=aAb) for ephemeral and classical gullies was established for the study area by means of log10-linear regression to analyze the evolution from ephemeral to classical gully.The resulting relationships are S_EG=0.052A-0.148_EG and S_G=0.072A-0.141_G,respectively,for ephemeral and classical gullies.Furthermore,a linear regression model for the prediction of total gully length at the catchment level was established using field data,and although it didnot successfully predict the length of individual gullies,it explained better the variation in total gully length in the catchment.