Abstract: Water quality and its spatial-temporal variation around a dam-site imply abundant information, which may reveal the interaction among water, rock and curtain and the change in seepage conditions. The Lijiaxia Hydropower Station is taken as an example, and the seepage water samples from different parts of the dam-site are tested. The spatial distribution characteristics are analyzed by using hydrochemical diagrams and conducting statistical analyses. The detection results are compared with those of the corresponding parts conducted before. The results show that the seepage water in the corridor is generally of high salinity, especially in the dam foundation. It suggests that the hydraulic connection in both sides of the dam abutment is more active than the one in the dam foundation. From the point of view of time evolution, the detection results in the corridors of the left bank and dam foundation are consistent with the previous ones, indicating that the corresponding parts of the anti-seepage performance show overall change. While the change in water samples on the right bank corridor is larger, which indicate that the hydraulic connection between some locations in the right bank corridor and the reservoir water before the curtain was more active than other places.