Recently, the purposes of river restoration works have became not only the protection for flood but also the restoration of ecosystem quality. In this context, habitat evaluation procedures are becoming important. The Instream Flow Incremental Methodology (IFIM) is one of the most popular habitat evaluation method, but still there is little application in Japan. In this paper, we study the accuracy and applicability of fish habitat evaluation method by IFIM. At first, we surveyed habitat variables, such as velocity, depth and substrate during the summer and the autumn in 1998 in the kiba River, Yamaguchi prefecture, to derive suitability-of-use curves, which are the core technique in IFIM. Then, we compare the observed fish distribution with calculated habitat distribution by using the suitability-of use curves obtained from the same river, which showed a good accordance. Next, we compare the observed fish distribution with calculated habitat distribution by using the suitability-of-usecurves obtained from literature and laboratory. The former showed a bad accordance, the latter showed a good accordance. Those results imply that the suitability-of-use curves obtained from a river will show a good accordance when it is used in the same river, and suitability-of use from laboratory can apply to other rivers.
