Abstract: By constitution of Regional Drought Index concerning drought-hit area in the whole province and different levels of drought intensity,we have used Abnormal Index to divide years into moderate,heavy and super drought ones.Based on NCEP/NCAR reanalyzing data,we have used morlet wavelet to investigate the trends of Intensity Index of Spring-Summer consecutive drought in Yunnan Province,as well as to compare and analyze the difference in200hPa and 500hPa circulation between the disastrous years of Spring-Summer consecutive drought and multi-year's average value. The results show that average frequency of Spring-Summer consecutive drought causing disasters in Yunnan Province is:Super drought happens once in20 years,heavy once in10 years,and moderate once in5 years.At present,Yunnan may be in such a historical position,either there is no Spring-Summer consecutive drought,or will be a super drought disaster.The 500hPa high latitudes is controlled in zonal circulation,and Qinghai-Tibet high-pressure is obviously weak,and the bay of Bengal low trough does not appear or obviously weak.The south area of 20°Nis controlled by positive anomaly zone,and has not convergence of cold and warm air in Yunnan.The 200hPa Qinghai-Tibet Plateau is in -50gpm strong negative anomaly zone,and the north part of Indo-China Peninsula is in -5gpm anomaly zone.These situations can not form the vertical circulation with a center in the northern part of Indo-China Peninsula and the upper-level divergence as well as the low-level divergence rising,which means that there is not an effective precipitation process to relive the drought.In addition,the east-west monsoon transition is later about 16d than usual,which bring on the Spring-Summer catastrophic consecutive drought in Yunnan province.