The effects of the solute properties in aqueous solutions on the separation characteristics in ultrasonic atomization were experimentally examined. For the aqueous solutions of monohydric alcohols (methanol, ethanol and 1-propanol) and ketone (2-butanone), the content in the accompanying liquid was larger than that in the residual solution. For the aqueous solutions of dihydric alcohol (propylene glycol), trihydric alcohol (glycerol) and amides (formamide and acetamide), on the other hand, the content in the accompanied liquid was smaller. From these, it was considered that the hydrophilic and hydrophobic properties of solute molecules govern the separation characteristics in ultrasonic atomization. For the aqueous solutions of carboxylic acids (acetic acid and propioloc acid) and inorganic salts (Li2SO4, Na2SO4, K2SO4,Rb2SO4 and CS2SO4), the content in the accompanied liquid was the same as that in the residual solution. These results indicate that ionized molecules in water were not separated by ultrasonic atomization.