Abstract:In order to study the drought conditions in the middle and lower reaches of the Yangtze river, the southwestern region, and the north China plain, we use the GRACE time-varying earth gravity field model from 2003-01 to 2012-12 to calculate the changes in the terrestrial water reserves of the three regions. The results show the lowest value of land water storage change of the middle and lower reaches of the Yangtze river plain and the north China plain occur in May 2011, and in the southwest region the lowest value is in March 2010. According to the water balance principle of land water reserves change, we calculate the changes of groundwater reserves in the three regions. The groundwater reserves in the middle and lower reaches of the Yangtze river and the southwestern region are slowly increasing with rates of 0.54 mm/month and 0.34 mm/month. The trend reduces to a rate of 0.33 mm/month in the north China plain. The loss of groundwater reserves in the three regions during the dry period are: -21.31 mm/month in the middle and lower reaches of the Yangtze river, -19.88 mm/month in the north China plain, and -15.72 mm/month in the southwest. Finally, we use the monthly rainfall and temperature data released by NOAA to quantify the rainfall and evaporation in the three regions during the drought period. The main cause of drought in the southwestern in the spring 2010 is the temperature anomaly. The main reason for the drought of the north China plain and the middle and lower reaches of the Yangtze river in 2011 is the lack of rainfall.