Abstract: Carbonate rocks are widespread along the south Tianshan, where the function of karst system depends on the texture of karst medium. It’s found that there are a lot of solution tectonic fissures, interlayer solution fissures, and solution joints in the carbonate rock strata through the karst investigation and analysis. According to the statistics, the density of solution tectonic fissures is to 1~4 per 10 m width, the fissure ratio on plane to 1.15%~5.71%, and the width of fissures to 10~500 mm, which are netted distribution and developed cross beds. The combination of all kinds of fissures compose a complicated karst system with the medium of fissuresolution fracture. The significance of the solution fissures system for the precipitation infiltration and water storage is analysed, and its function of transmission and storage in the process of hydrological circle is clarified as well. At last, a new method of relieving the lack of water resources and renovating the karst environment at the edge of Tarim basin is put forward, namely translating the surface runoff into underground seepage and reducing the evaporation in order to increase the recharge of precipitation in karst mountain areas through engineering measures.

Key words: karst system, characteristics of medium, water resources, south Tianshan, Tarim Basin