Abstract: According to the hydrogeological property and laws of water abundance,well samples were selected and analyzed.The result showed that among the 54 wells in Xiangxi autonomous prefecture there were 13 wells with excellent water quality,33 wells with good water quality,7 wells with poor water quality and 1 with awful water quality.The average composite index of 33 water wells surveyed ( clean included ) was 2.548,and the composite index of 21 pollution monitored wells（hot point included）was 1.935；there was no industrial and urban pollution surrounding 6 wells,and the water quality composite index of the wells was 1.182,which was obviously superior to others.The quality of underground water of Xiangxi autonomous prefecture is not optimistic and the underground water needs to be protected immediately.

Key words: Xiangxi autonomous prefecture, underground water, chemical feature of water