Based on the historical record,dry/wet series since 1470-2008 AD in Northwest China were reconstructed and analyzed.The dry/wet series for 7 regions are expressed by five grades,and dry/wet climate is obtained from a cluster analysis on annual data during 1470-2008 at 19 stations in Northwest China.The variation feature of the dry/wet series,such as phase characteristics,periodicity and abrupt change,are presented. The results show that the reconstruction of sequence reliability is high,and it can be used as a dry/wet climate change research.Wavelet analysis shows that those periodicities existed in the last 500 years,such as the periods of around 11 year,25-35 year,80-100 year.Among them,11 years and 35 years periodicities in the whole analysis period are relatively stable than80-100 years periodicities.The signs of abrupt changes in the 7 regional dry/wet series were detected by moving t-test.It is indicated that abrupt climatic changes have occurred for every regions in Northwest China during 1470-2008 AD.Both edge of the study area, such as Shaanxi and Yushu,abrupt signal appears fewest times;Ningxia and Golmud is second;the signal appears most times in the middle study area such as Lanzhou,Zhang ye,Xining.It means middle area is the sensitive area of dry/wet climate change.The dry/wet abrupt signal mainly concentrated in the 17th century, dry/wet climate change in recent century is relatively stable.