The variation features of the shape factor of probability distribution of single wave overtopping volume on vertical wall is investigated in detail by carrying physical model test.In the test the wave pattern ranged from completely nonbreaking to fully breaking ,meanwhile two slope ratios at wall toe,three wave steepnesses and three relative freeboard heights are included.The result shows that wave steepness has no clear effect on the shape factor.Increment of relative freeboard height causes decrement of the shape factor in different level depending on the relative depth and slope ratio.With relative depth increasing the variation of the shape factor changes with slope ratio from increment to decrement gradually.In the variation process of relative depth from deep to shallow the shape factor firstly increases successively,then reaches its peak and begins to decrease at last.The global mean of the shape factor both in nonbreaking and breaking condition region in the test agree to that of the existing studies.