Choosing the 73 years of by-minute rainfall data from 1941 to 2013 at Beijing Meteorology Observation,we extract the rain samples of 60 min and 120 min， and select the appropriate matches for using Pilgrim &Cordery method to compute the Beijing short lasting design storm pattern. Two schemes can be employed to analyze the design storm pattern: One of rainfall samples are taken from the natural rainfall events， another intercepts the maximum rainfall by minutes. The results show that rainfall patterns of 60 min and 120 min by the two schemes have the same shape， i.e., both have single peak pattern and the peak position is near the front. But two schemes result in different rainfall distribution proportion. Accounted for the total rainfall peak proportion of rainfall patterns of the 60 min and 120 min， the natural rainfall processis 3.79% and 5.83% higher than the maximum lasting process, respectively.