Aiming at the setting conditions and theoretical calculation of storm water infiltration equipment,we analyze and study the domestic and overseas codes.Combining with the implement scheme of infiltration equipment of an overseas port engineering,we calculate the infiltrated water volume and water storage of infiltrated pipe trench,infiltrated chamber and infiltrated channel according to the rainfall intensity at the different rainfall time,and determine the economical dimensions of infiltration equipment.The engineering example shows that on the condition of the rainfall is no more than 91 mm/h and the soil permeability is no less than 0.5 mm/s,this infiltration equipment has obvious advantages in storm water discharge.