Abstract: Differences between formulas applied in engineering design departments of South Korea and in Chinese hydraulic engineering for calculating flow capacity of the flat-bottomed sluices and orifice flow are compared.Results show that influences of the approach velocity head before a sluice should be considered in calculation.Hydraulic model tests for the design scheme and comparison scheme of the floodgate of the Soli River in South Korea are carried out,and the results show that the comparison scheme is better than the design one in terms of flood control.