Abstract: This paper takes the Dananhu mining areas as an example,which is located in TurPan-Hami Basin. Com- bined with the typical hydro-geologic characteristics in its Jurassic containing coal formation such as good permeabili- ty,water rich,static large reserves,through the method of field investigation,the nine water samples taken along the main groundwater recharge direction were used to conduct the isotopes analysis and chemical tests. Based on the water isotopic characteristics obtained in the study area and the precipitation line of hydrogen and oxygen isotopes construc- ted in Hami area for the first time,the authors systematically studied the conditions about groundwater recharge in east- ern Tianshan area. Considering the characteristics of arid area and water controlling function of main structure in the study area,the authors clarified the forming reasons in the water cycle conditions of the special groundwater system in the Dananhu depression. The results of this study show that the snow melting water in the eastern Tianshan foothill is the only one source to supply for regional groundwater by replenishing of the deep penetration. Its main flow direction is from northeast to southwest. Controlled by same geotectonic movements,such as North schallsee uplift,the rise of the Western and Southern Jueluotag,and eastern boundary fault and others faults,the general hydro-geological conditions of the study area are relatively closed and the groundwater circulation is poor. Then the Jurassic aquifer formation in the area is characterized by its static reserves and high salinity.