In this study, the multi-functional fishway with underground passage, sediment block system reflect the fish's ecological characteristics and many kinds of fish up and down easily is proposed. The 3D-analysis of Reinforced Concrete(R/C) Slab and R/C + Steel Concrete(S/C) Slab with rectangular underground passage are carried out by SAP 2000 software program about multi-functional fishway's durability.
The Slab analysis results show that the R/C Slab type of the maximum stress is decreased by 27.8 than that of R/C + S/C type(Size:0.8m x 0.1m, Velocity: 1.6m/sec)and the shortage of shear is 31.9 than that of R/C + S/C type(Size:0.8m x 0.2m, Velocity: 1.6m/sec). The stability of R/C + S/C concrete slab with underground passage is more favorable than that of R/C concrete slab.