Based on daily precipitation data for 145 meteorological stations in the Huang-Huai River Basin over the last 50 years (1961-2010),we selected the Standardized Precipitation Index (SPI),the frequency and range of droughts and floods,and combined morlet wavelet analysis and Empirical Orthogonal Function (EOF)to analyze characteristics of droughts and floods. The results show that,on time,the basin had a trend of warm and dry in the last 50 years. The basin has experienced four phases,1961-1977 was a wet period and the basin was flooded overall. From 1978-1985 was a normal period,in addition,flood event occurred in 1983,the rest area around zero. From 1986-2002 was a dry period,the SPI index value was almost less than 0. The basin was in drought status overall. From 2003-2010 was a transition period,after the moderate flood event in 2003. The drought situation improved,the SPI index was gradually within the normal range. On time,the range of moderate droughts presented a major period of 10 years,other range of droughts presented a major period of 20~25 years;the range of flood gradually reduced. The mutation point of four kinds of range of drought and the range of moderate floods,moderate flood and severe floods were 1977 to 1978. The range of extreme floods is gradually expanding,but not notable. On space,flood frequencies were lower than drought frequencies in the study area,changes in the Haihe River Basin and Yellow River Basin were basic synchronization;changes in the Huaihe River Basin were contrast. Because of the combined effects of latitude and monsoon factors,changes in the study area were zonal and showed an anti-phase change at a north-south latitude of 37°.