Indices of structure density,measured sediment blocking capacity,and single-dam control area were surveyed,compiled and analyzed for the large and medium sized check-dams in Northern Shaanxi Province in the special action of check-dam safety inspection.The results show that the total control area of large and medium sized check-dams was 28703.84 km² and the total sediment discharge reduction was 4.11@10¹⁵kg,highlighting the critical role of check-dams on sediment blocking and silting.Positive pair-wise correlations were found significantly among building density of check-dams,capacity of sediment blocking and control areas of the single-dam.The silted check-dams of Yulin City were utilized mainly for crops limited to a few species only,while in Yan.an City,the silted check-dams were confined to sediment holding only.The management and protection of check-dams were conducted collectively through governments.The most serious potential safety hazard of the check-dams could be the hidden danger in the dam body.