The paper investigates the effectiveness of wave dissipation of a new type of breakwater which is a floating structure with vegetation planted.Under the premise that the height of the vegetation is higher than the wave,the factors influencing the effectiveness of wave dissipation of the floating wave dissipater in unidirectional regular wave environments are analyzed.Based on comprehensive experimental flume data,the effectiveness of wave dissipation of the floating wave dissipater with vegetation planted under regular wave are correlated with the plant density,relative width of the structure and wave steepness.The experiment results show that the plant density and the relative width of the structure are the most important factors affecting the wave dissipation,and this floating wave dissipater with vegetation planted plays a significant role in wave dissipation.