This paper presents an experimental approach to observe the drift woods capture effect of steel frame structure on the woody debris. The hydraulic model experiments with various parameter of column's span (W) and maximum or average length of drift woods (lmax or lmean) are carried out. After checking the capture mechanism of drift wood capturing structure to the drift woods, the capture ratio corresponding to the representative parameters, i.e., ratio of column's span to maximum length of drift woods (W�^lmax), are discussed. Finally, mutual relationship was sufficiently estimated from the experimental results.

Key words�Ftrap performance, woody debris, drift wood capturing structure