Based on monthly measured precipitation data of 60 meteorological stations over circumBohairegion from 1961 to 2013

the level and distribution years of the drought and flood were determined by using  Z  index. In order to explore the relative mechanism of the drought and flood over circumBohairegion

correlation analysis between the Sunspot activities and the drought and flood

and between ENSO events and the drought and flood was conducted

respectively

by using frequency analysis and Morlet wavelet method. The results showed that: ① The drought and flood occurred frequently

and the drought was slightly higher than the flood over circumBohairegion from 1961 to 2013.  ② There was a significant negative correlation between relative Sunspot number and drought and flood index

and a significant positive correlation between relative Sunspot number and drought and flood level. The frequency of occurrence of the drought and flood in the Sunspot maximum years was higher than in the minimum years

and the drought was significantly more than the flood in the Sunspot maximum years. It was prone to the drought in singular cycle of Sunspot activity

while the drought and flood occurred alternately within dual period of Sunspot activity. ③ There was a significant negative correlation between ENSO events and drought and flood index

and a significant positive correlation between ENSO events and drought and flood level. The frequency of the drought and flood was the same in the EL Nino years and LA Nina years

and probability of the drought was significantly higher than the flood in the EL Nino years. ④ There was a good corresponding relationship between the Sunspot activities and small scale period of drought and flood index

namely

the quiet period of Sunspot corresponded to the abundant precipitation period and the active period of Sunspot corresponded to the less rainfall period

indicating that the Sunspot activities had a great influence on the alternating of drought and flood. The corresponding relationship was not consistent between ENSO events and small scale period of drought and flood index with the existence of staggered phenomenon

while ENSO events had great effect on the slipping of each scale period of drought and flood index.