In 1923 Great Kanto Earthquake attacked the south Kanto region. By the strong shock caused by this quake, in West‐Tanzawa mountain area enormous number of hillsides collapsed and huge volume of unstable sediment was yielded. In order to prevent sediment disasters, restorative SABO works such as check dams and hillside works were executed by the Ministry of Home Affairs, the Department of the Imperial Household and local governments. Kitao Moroto, Professor of Tokyo Imperial University, remained many photos and memoirs concerning these SABO works and disasrers. These materials were taken and written on the basis of his field trips around West‐Tanzawa mountain area. Through referring to these materials and our field investigations in recent several years, we have confirmed that these many SABO works were implemented by Moroto’s guidance and in close coordination with the executive organizations. Hence many check dams remain and have been effectively consolidating foots of hillsides and reducing overabundant sediment runoff to downstream. These check dams have some characteristics in those days when modern SABO technologies extended in all over Japan.