Abstract: Based on 53 years observed data of rainfall in Beijing,the annual maximum series method,the annual exceedanee series method,the partial duration series (rainfall depth over threshold) method and the annual multi-sampling series method were separately used to process rainfall depth data.Four candidate distributions (log normal,PearsonⅢ,log PearsonⅢand Gumbel) were used to fit the observed data and find the most appropriate distribution.Distribution parameters were estimated using the moment method. The assessment was based on the Chi-Squared test and Kolmogorov-Smirnov test combined with root mean squared error.On the basis of these comparisons and estimation results,it can be concluded that,if the length of rainfall records is shorter or selected return period is less than one year,the annual multi-sampling series method is proposed,otherwise,the annual maximum series method is proposed.The Pearson lit distribution is the most appropriate distribution for Beijing rainfall data.