To study the influential factors of the hydrodynamic characteristics of the catenary single pontoon breakwater,we carry out two-dimensional physical model experiment to study the variation of the transmission coefficient Kt of the floating breakwater model and the maximum tensile force F on the catenary chain,and discuss the influence of parameters including the draught S/d,the relative width B/L,the chain stiffness k,and the mooring inclination angle α on the hydrodynamic performance within 2D regular waves.The average wave height is used to calculate the transmission coefficient Kt and the average value of the previous 1/10 maximum pulling force is used as the maximum pulling force F.The results show that when the relative width B/L is less than 0.3,the relative width B/L is the main factor affecting the wave dissipation performance of the floating box model,and when the relative draft S/d is less than 0.14,the relative draft S/d is the main factor affecting the maximum tensile force F on the mooring chain.The results obtained can provide reference for the design and further research of the catenary single floating box breakwater.