Li2O–B2O3–P2O5 glass soot was fabricated from aqueous precursor solution of a CH3CO2Li·2H2O and BCl3, POCl3 by the flame-assisted ultrasonic spray hydrolysis. The aqueous precursor solution of the lithium acetates was first atomized with an ultrasonic vibrator (1.7MHz). B2O3 and P2O5 were formed from BCl3 and POCl3 by oxy-hydrogen flame. Their properties were investigated by SEM, XRD, TGA–DSC and impedance analyzer. The formed particles in glass soot had spherical shape and the size of approximately 50–100nm. XRD analysis revealed that the amorphous phase and crystalline phases were mixed in glass soot and the crystalline phases were B(OH)3 and B2O3. The crystalline B(OH)3 and B2O3 found in glass soot completely disappeared by heat treatment. Conductivity was measured by complex impedance method using impedance analyzer and the conductivity was 10−8 S/cm.