Abstract: Ephemeral gully is often characterized by the small channels that formed by surface runoff. They can tend to reappear in the same location, despite temporarily eliminated by tillage. Among them, the ephemeral gully erosion is one of the main types of the soil erosion in the cultivated land in the typical black soil region of Northeast China. There is the serious threat to the land productivity and crop quality. This study aims to investigate the interannual and spatial variation in the ephemeral gully erosion. A prediction model was also developed after investigation. UAV surveys were conducted over two consecutive years in the black soil region of Northeast China. The ephemeral gullies under rainfall runoff generally reached their peak development by the end of the rainy season in late September. There was the significant influence of the crop cover before harvest, due to the uncertain time of the autumn harvest over the different regions. The ephemeral gullies were disturbed after harvest. The UAV measurements were difficult at a regional scale. Once the rainfall of the year was accumulated in early summer, the ephemeral gullies were already redeveloped suitable time for the UAV surveys, with the still relatively low crop cover. Therefore, the UAV surveys were conducted from June 28 to July 29 in 2022 and from June 8 to July 1 in 2023. All sample units were covered in Bin County, Bayan County, Baiquan County, Hailun City, Mingshui County, Keshan County, and Nenjiang City. DSM and imagery were acquired with an accuracy of approximately 3.8 cm. The morphologies of the ephemeral gullies were captured to determine their influencing factors. The results showed that: 1) The intensity of the ephemeral gully erosion exhibited the significant interannual variation in the differences of the rainfall. The proportion of the units with the observed ephemeral gullies was 75.78% and 74.24% in 2022 and 2023 among 66 survey units, respectively. The average density of the line, area and volume in the ephemeral gullies decreased by 31.67%, 36.72%, and 40.78% in 2023, respectively, due mainly to the lower rainfall during the same period. 2) The 215 ephemeral gullies were identified in the 50 survey units in 2022. While in 2023, 151 gullies were found in 49 units, totaling 366 gullies over the two years. The average gully length, area, and volume were 99.26 m, 232.92 m², and 35.76 m³, respectively. The number of gullies in 2023 was only 70% of that in 2022. The average length, area, and volume decreased by 16.06%, 23.55%, and 28.06%, respectively. 3) The 46 ephemeral gullies with the complete catchment areas were identified in 2022, where 27 reappeared in the same locations in 2023. Whether a gully reformed was significantly influenced by the catchment area and runoff volume (P < 0.05). According to these 73 gullies, the ephemeral gully development was found to be significantly affected by the catchment area and runoff volume. The length, area, and volume of the gullies exhibited the significant power-law relationships with the average catchment slope (S) and runoff (Q). The prediction models were developed (n = 73, P<0.05):A power function model for shallow gully length (L), area (A), and volume (V) was developed with catchment average slope (S) and runoff (Q) as independent variables. These findings can provide a valuable reference to control and predict the ephemeral gully erosion at regional scale.