  SDSS J094857.3+002225 is a very radio-loud narrow-line Seyfert 1 (NLS1)
galaxy. Here, we report our discovery of the intranight optical variability
(INOV) of this galaxy through the optical monitoring in the B and R bands that
covered seven nights in 2009. Violent rapid variability in the optical bands
was identified in this RL-NLS1 for the first time, and the amplitudes of the
INOV reaches 0.5 mag in both the B and R bands on the timescale of several
hours. The detection of the INOV provides a piece of strong evidence supporting
the fact that the object carries a relativistic jet with a small viewing angle,
which confirms the conclusion drawn from the previous multi-wavelength studies.
