A good correlation exists between drought and underground general circulation. Based on about the data of drought of recent 50 years, there are 4 types in total of who create drought. The first is large underground cold vortex, the second is large negative area anomaly of inter-monthly (inter-seasonal) underground temperature of 3.2 m depths. The third is serious drought before strong earthquakes (drought-earthquake relationships). The last one is region that cold vortex stayed after a macroseism. Further more, we found that cold vortexes slowly move because of its long wavelength, and droughts result from cold vortexes are usually more serious. Negative anomaly of underground temperature of 3.2 m depths shows a weakened thermal process, it can be seen a signal to predict rainless the next month. After all, both serious droughts and floods of China are related to strong earthquake.