To further analyze and demonstrate the drainage capacity of a harbor,taking a large container port in Guangzhou as an example,we build a drainage model based on InfoWorks ICM software of the harbor.To demonstrate the flood control capacity of the common container yard and the new-type concave storage yard,we analyze indicators by simulating the rainfall process with different recurrence interval,such as the number of overflow nodes between different storage yard types,the time when the deepest seeper appeared and the maximum seeper depth.The results show that the flood control capacity of the harbor is obviously improved after the adoption of the new-type concave storage yard,and the concave storage yard shows obvious storage function.