The determination of design storm is an important foundation for the planning and design of urban flood protection and drainage projects. The paper takes the central area of Nanjing City as the research area. First, the storm rainfall intensity formula was used to calculate the stormwater volume at different recurrence periods of 60 and 120 min, respectively. Then the annual maximum rainfall sequence was selected based on precipitation data from 1982 to 2015 and the synthesized rain-peak modulus was calculated. Finally, the Pilgrim & Cordery pattern and the Chicago rain pattern methods were used to deduce the design storm process lasting 60 min and 120 min in the central area of Nanjing, and the peak size, rain peak position and accumulated rainfall before the rain peak were compared. The results showed that the rainstorm peaks of 60 min and 120 min are at the time of 1/2 and the first 1/3 of the whole rainfall process, respectively. The rainfall peak values obtained by the two methods are not significantly different. The rainfall calculated by Pilgrim & Cordery pattern when the peak appeared is larger than that of the Chicago pattern. The Chicago pattern is recommended for the short duration design storm. The research results provide a reference for the urban waterlogging risk assessment and drainage and waterlogging prevention project planning and construction in the central area of Nanjing.