Six-year (2005–2010) evolution of water chemistry(Cl^-, NO₃^- SO₄^2- HCO₃^- Na⁺, K⁺, Ca²⁺ and Mg²⁺) and their interactions ith morphological properties (i.e., slope and area), land cover, and hydrological seasonality were examined to identify ontrolling factors and processes governing patterns of stream water quality in the upper Han River, China. Correlation nalysis and stepwise multiple regression models revealed significant orrelations between ions (i.e., Cl^-, SO₄ ^- Na⁺ and K⁺)and land cover (i.e., vegetation and bare land) over the entire catchment in both high- and low-flow periods, and in the buffer zone the correlation was much more stronger in the low-flow period. Catchment with steeper slope (.15u) was egatively correlated with major ions, largely due to multicollinearity of basin characteristics. Land cover within the buffer one explained slightly less of major elements than at catchment scale in the rainy season, whereas in the dry season, land over along the river networks in particular this within 100 m riparian zone much better explained major elements ratherthan this over the entire catchment. Anthropogenic land uses (i.e., urban and agriculture) however could not explain water chemical variables, albeit EC, TDS, anthropogenic markers (Cl^- NO₃^- SO₄^-, Na⁺, K⁺ andCa²⁺ significantly increased during2005–2010, which was corroborated by principal component analyses (PCA) that indicated anthropogenic inputs. Observations demonstrated much higher solute concentrations in the industrial-polluted river. Our results suggested thatseasonal evolution of water quality in combined with spatial analysis at multiple scales should be a vital part of identifyingthe controls on spatio-temporal patterns of water quality.