The structure and mechanical properties of Y-TZP nanoceramics produced by ultrasonic (US) action on nanostructured ZrO2 – 5.4wt% Y2O3 powder have been analyzed. The influence of powder US-treatment on elastic aftereffect of a compact, uniformity of ceramics volumetric shrinkage, on ceramic nanostructure forming and as a result on its density, hardness, impact strength was shown. The optimum of power level of US-action was defined.