The amplitude absorption coefficient α for continuous ultrasonic waves in aqueous solutions of copper acetate, sodium acetate, and potassium acetate has been measured over a range of frequency from 7 to 45 mc, at temperatures between 5° and 50°C, and at concentrations up to 0.5M. The experimental values for copper acetate solutions confirm the existence of a relaxation frequency at about 18 mc (at the higher concentrations). The results for sodium and potassium acetate solutions show an absorption coefficient below that of pure water at the higher frequencies. They also indicate the existence of relaxation frequencies below 10 mc.