Аннотация:Ecotoxicity estimation of nanodioxide titanium and nanodiamonds conducted by means of bioassay methods in standardized test-systems showed that in most cases with authentic deviation of values experimental test-functions from control it is possible to detect an influence of nanomaterials on mortality Paramecium caudatum, Daphnia magna and root growth of seeds of the higher plants Brassica juncea. The tendency of the toxic effect increased with the reduction of the nanodiamond particles size is observed. In the investigated range of nanoparticles concentration (5-500 mg/l) aren't revealed authentic correlation between concentration indicators and "responses" test-cultures.