The Hekouzhen-Longmen Reach (He-Long Reach) in the middle of the Yellow River is the primary source area of sediment of the Yellow River. Check-dams are a widely used measure for controlling soil and water losses in this area. To explore the response of sediment retention by check-dams to the "Grain for Green" project in the He-Long Reach, the authors investigated the sediment deposition of eleven check dams and collected the data of sediment yield from another twenty-nine check dams using literature integration. The results indicated that the average annual dam-trapped sediment yields in the northern, middle, and southern region of the He-Long Reach all tended to decline over time and were drastically different between different periods. After the "Grain for Green" project, the average annual dam-trapped sediment yields in the northern, middle, and southern region of the He-Long Reach were 7138.5 t km^-2 a^-1, 2596.5 t km^-2 a^-1, and 4230.9 t km^-2 a^-1, respectively, which decreased by 49.5%, 84.1%, and 52.1% compared to those before the project, respectively. Furthermore, the average annual dam-trapped sediment yields in different regions of the He-Long Reach were all significantly less than those before the "Grain for Green" project. The overall soil erosion severity on dam-controlled watersheds in the northern, middle, and southern region of the Reach turned into high, moderate, and moderate from very high, severe, and very high, respectively. Before the "Grain for Green" project, the average annual dam-trapped sediment yields in the middle and southern regions of the He-Long Reach both declined over time, being drastically different between different periods. Among the three sub-zones in the Reach, the effects of the "Grain for Green" project on reducing sediment yield increased in the following order:the northern region < the southern region < the middle region. This research demonstrates that the "Grain for Green" project and erosion control practices can both effectively reduce erosion sediment yield of small watersheds. In future, the construction of check-dams in the He-Long Reach of the Yellow River should be appropriately reduced to save soil and water resources and guarantee water security downstream.