<p>A functionalized nanostructure aminopropyl aerosilogel (amino-ASG) effective in the sorption of strontium ions has been synthesized using a single-stage liquid-phase chemical modification of the surface of hydroxylated mesoporous aerosilogel, which has been characterized by IR spectroscopy, low-temperature nitrogen adsorption-desorption, and chemical analysis. It is shown that amino-ASG selectively removes Sr²⁺ cations from binary solutions at pH 1.0-10.0, even under a 10-fold excess of Ca²⁺ cations, with equilibrium being reached during 5 min. It is established that the sorption kinetic for functional amino-ASG is described by a pseudo-second-order equation. The equilibrium sorption is consistent with the Langmuir adsorption equation, which proves a decisive contribution of the grafted amino groups.</p>