The Dongting Lake system includes the Xiangjiang River,the Zijiang River,the Yuanjiang River and the Lijiang River.The contents of 28 elements:Ag,As,Au,Ba,Ce,Co,Cr,Cs,Eu,Fe,La,Lu,Mo,Na,Nd,Rb, Sb,Sc,Sm,Sr,Tb,Th,U,Yb and Zn in the river water from the Dongting Lake system have been determined with the Neutron Activation Analysis method.The average contents of these 1elements are all within the range of element compositions of the world fresh water,and close to the low limit of the ranges.The coefficients of variations of contents are wthin 0.72 for most elements.In comparison with other river water,the contents of Pe,Th and Re REE in the Dongting Lake system are lower,but the contents of Rb and Cs are relatively high.That is mainly caused by the influence of the hydrochemistry and geochemistry.The reason why the environmental background values of almost elements in the reservoir water are higher than in river water is discussed in the paper.The human activities might result in the increase of the environmental background values of elements.Finally,the percentage by content of 18 elements in soluble and suspended state and forms are also discussed.