The summer rainfall series (June to September) in the Haihe River basin from 1800 A.D.to 2012 A.D.are reconstructed by statistic method,using data of the observed precipitation and the dryness and wetness grades in modern times.The quantified reconstruction of historical precipitation,with its feasibility and reliability areintroduced,and the time series of the reconstructed data are analyzed in this paper.The results show that the summer rainfall is always fluctuating and there are 13 shift terms in the basin during 1800-2012.Summer rainfall is generally less in the 20th century compared with that inthe 19th century,and the decreasing trend is most obvious in the last 100 years and the last 60 years.The 1880s-1890s is the moistest period,while the 1990s-2010s is the driest period.Power spectrum and wavelet analysis also show that the summer rainfall during 1800-2012 is characterized by inter-annual and inter-decadal oscillations with 2-8 a,10-15 a,22 a,25-30 a,quasi-35 a,and quasi-55 a period,and the long period oscillations are shortened in the 20 century.