Abstract: Based on the analysis of computing formulas of scour depth around spur dikes all over the world and the characteristics of hydrology and sediment in the Yangtze River Estuary, a suitable computing model for the scour depth around a typical spur dike in the Yangtze River Estuary is elaborated in the paper . According to the measured data, the practicality of the computing formulas is verified, and the estimated formula for the initial scour velocity in front of the dike is given.