By integraing the phenomena of wave deformations on a slopping bottom, and water discharge, a simple wave dissipation facility which assembles with a slopping bottom, a wave dissipating room and a bottomed discharge system was proposed. The major concept is to reduce and to prevent the reflection waves and thus might improve the water surface ocsillations from the superpositions of incident waves and reflected waves. Through the numerical simulations with CFD and the hydraulic model tests in a wave flume, the new conceptual structure was found to have good wave dissipation function even in long period incident wave cases with 40 sec wave period. This paper also discussed the design criteria via correaponding runup and overtoopping theories.