Based on the physical model experiment,we study the wave run-up and mean overtopping of vertical breakwaters with the wave return wall under irregular wave,and analyze the influence of main factors such as the levee free-board,horizontal extension of wave return wall and wave evenness.The results show that the main factor affecting the wave run-up is wave height,but wave period has little effect on it.Furthermore,the levee free board,horizontal extension of wave return wall and wave evenness are important determinants of the mean overtopping of vertical breakwaters.It is noteworthy that the extent of influence of horizontal extension of wave return wall is related to the levee free-board.On the basis of the physical model experiment,the new calculation formulas on the wave run-up and mean overtopping of vertical breakwaters are set out,which can serve as a reference for the engineering design.