The geochemistry of major ions(Ca2+，Mg2+，Na+，K+，HCO32-，SO42-，Cl-，NO3-和SiO32-)in the Yangtze River was studied, based on the monthly monitoring data at Xuliujing station for the period of 2004-2008 and the investigation result of the Yangtze River in September 2008. The study found that the concentration of main ions varies clearly in different seasons, with a negative correlation with the discharge of the River. But the difference of the concentration is less clearly than that of the discharge. There is a persistently increasing in the concentrations of K+, Na+, Ca2+, Mg2+, Cl-, NO3-, SO42-and the ratio of hardness/alkalinity; especially the concentration of SO42-and the ratio of hardness/alkalinity have a more obvious increasing trend. In contrast, the concentration of SiO32-and HCO3-show a decreasing trend. The changes of major ions mainly result from the environment acidification, the pollution emissions by human, the cyclic salt from sea, the preserved effect by reservoirs establishments etc.