Groundwater of the unconfined aquifer in Tao'er River Basin was systematically sampled and analyzed in dry and wet season in 2003, respectively, the methods of the spatial variograms and Kriging interpolation were applied to analyze the spatial and temporal variation characteristics of the total dissolved solids (TDS), the results indicate that (1) the values of TDS vary unconspicuously between seasons, but present clear patterns; (2) the range values of TDS is up to 64.8 km and 67.2 km, respectively, which are subject to the large scale factors such as hydrogeological conditions, topo-physiognomy and the type of soil and so on; (3) TDS represent abnormally due to saline pollution in the some area, but so far the activities of human being don't make the important influence on the quality of the regional groundwater.