For the purpose of improving the riverbed environment, Japanese traditional river works "Seigyu"(Crib spur) were set up in the Kizu River as a test trial in December 2017. Although their environmental effects through geomorphological change are under surveying even now previous knowledge on the effects has never been enough for detecting the most suitable location for setting this kind of traditional river works. Therefore, we have reviewed the past installation sites of the traditional river works in order to detect the geomorphological and hydraulic characteristics of the sites. The results indicated that a range of variations in the bed slope among the types of traditional works was related to functional difference and suitable site conditions for each type of the works.