In this research, a simple ultrasound-assisted method has been used for the preparation of lead oxide nanostructures in the presence of polyvinyl alcohol (PVA) as a capping agent. Different concentrations of PVA were added to the mixture to control of nanostructure size. The as-prepared lead oxide nanostructures have been investigated by UV-V is spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). UV-Vis spectroscopy results show a shift in the peaks and broadening with increasing of PVA amount. The XRD pattern indicates the uncapped sample contain mixture phase of lead oxides and PVA-capped samples were high purity and no other peaks were observed. The average crystallite size of nanoparticles was estimated using Debye-Scherrer's formula and the measured sizes reveal clearly the crystallite size decreases with increasing PVA concentration. The SEM results show by increasing in capping agent concentration, the distribution of nanoparticles has been changed. FT-IR Spectroscopy results show by increasing of capping agent concentration the energy between the functional group is changed and some peaks show a slight shift.