The results of researches of element composi-tion of water of the river Shagan in the territory of the former Semipalatinsk test proving ground are presented in the study. In the line with the river of Shagan is available an artificial reservoir the lake Atomnoye which is the result of industrial nuclear explosion. The main attention on the ground was paid to radio nuclide pollution as the source of dan-ger to local population. At the moment in the flood-plain of the river of Shagan is conducted unauthor-ized economic activity, i.e. cattle pasture. The available information was not enough, and the as-sessment of the quality of water requires the study-ing along with radio nuclide, also the element struc-ture. The concentration of the studied elements the content of strontium in hundreds of times, and other chemical elements (CE) tenfold exceeds average values for river waters, including. The excess of maximum concentration limit is noted for lithium (5 maximum concentration limits), iron, strontium and uranium (1 maximum concentration limit). The increased concentration of the number of elements were dated for sites 4-6; 8-11; 50-54; 63-66; 73-79; 84 km from the lake Atomnoye. The decrease in the studied elements on the site of confluence of the river Shagan in the Irtysh River (106 km) is not-ed on average. High concentration of these ele-ments as lithium and strontium is caused by these elements’ being highly fluent and having the ability to intense concentrating in salty waters of arid cli-mate are capable to considerable concoction. The sites at the beginning of the course from the lake Atomnoye with the raised maintenance of CE were revealed according to early researches; testify to the receipt of elements with ground waters on tec-tonic breaks. Thus, features of element composition of water of the river Shagan are locally connected with hydrogeochemical (with the mechanism of subcurrent of ground waters) and climatic factors.