Heavy metals are one of the environmental pollutants that have a serious impact on the environment. The analysis of hydromacrophytes growing in small rivers of the south of Kazakhstan with different contents of heavy metal salts revealed that morphometric indicators of the same plant species differ significantly depending on the level of total mineralization of the aquatic environment in different rivers of the Turkestan region.It has been established that two plant species can be used to bioindicate the content of lead ions in the aquatic environment: Azolla caroliniana Willd. and Veronica beccabunga L., which must be introduced into the tested aqueous solutions in the amount of 1.0 kg/ m3 and 1.5-2.0 kg / m3, respectively, to fully cover the water column at different depths. The first morphological changes in plants in the form of destruction of the structure of chloroplasts along the edges of unfolded leaves in A. caroliniana Willd. and slight withering of the lower underwater leaves in V. beccabunga L. there is already a 1.5 mg/l Pb2+ content in water, and a further increase in the content of lead ions in water to 600,0-800,0 mg/l leads to the death of plants.