PbO-B<sub>2</sub>O<sub>3</sub> glasses were prepared by traditional melting method. XRD and optical spectra measurements were done
to check properties. Second-harmonic generation was observed in the glasses induced by thermal treatment and
thermally poling process, respectively. But second-harmonic generation intensity was normally larger for the
later, and it increased with increasing PbO content, poling voltage, temperature and time. The mechanism of
second-harmonic generation in the PbO-B<sub>2</sub>O<sub>3</sub> glasses was also discussed. A promising material for all-optical
switching devices is expected.