Abstract: The problem of urban waterlogging in China is becoming more and more serious due to the inadequate drainage capacity of pipes or the aging of the drainage pipe network, so it is necessary to assist urban pipe network reconstruction with hydraulic model.Considering that designed rainfall pattern is an important factor affecting the design standard of the drainage pipe network, we took Liede River drainage area in Guangzhou City as the study area to analyze the impact of two short-duration designed rain patterns on the operation state of the pipe network, including overflow and fullness degree of pipes.The results showed that the rain-peak coefficient of Chicago rainfall pattern was 0.35,and the rainfall was concentrated near the rain-peak.The rainfall fluctuation of P&C rainfall pattern was distributed in the first half of the period, and the main rain-peak coefficient was 0.16.The number of water-filled pipes and the number of inspection wells where overflow occurred under Chicago rainfall patternwere both greater than those under P&C rainfall pattern, which put higher design standard requirements for drainage pipes.The total overflow and overflow of a single inspection well under P&C rainfall pattern were larger than those under Chicago rainfall pattern, which had a greater impact on surface ponding.In the 10-year designed situation, the difference between simulation results of the two rainfall patterns was the largest.Through quantitative analysis on overflow and water-filled pipes under the two kinds of rainfall patterns, we hope to provide a reference for the design and reconstruction of the urban pipe networks.