Abstract: In this work the results of experimental research of the sonoluminescence of water and biological liquid (plasma of blood) at different temperatures are described. The studied blood plasma was taken from normal and pathological patients. Sonoluminescence of water was found to decrease with a decrease in temperature. Samples of normal blood plasma produce sonoluminescence with approximately constant intensity at cooling. In contrast, sonoluminescence of pathological blood plasma increases with decreasing temperature. These results can be useful for investigations of the nature of sonoluminescence as well as for medical diagnostics.