  In this paper, a total of about 28000 images in $V$ and $R$ band obtained on
161 nights using the one-meter optical telescope at Weihai Observatory (WHO) of
Shandong University since 2008 to 2012 have been processed to measure the sky
brightness. It provides us with an unprecedented database, which can be used to
study the variation of the sky brightness with the sky position, the moonlight
contribution, and the twilight sky brightness. The darkest sky brightness is
about 19.0 and 18.6 $mag$ $arcsec^{-2}$ in $V$ and $R$ band, respectively. An
obvious darkening trend is found at the first half of the night at WHO, and the
variation rate is much larger in summer than that in other seasons. The sky
brightness variation depends more on the azimuth than on the altitude of the
telescope pointing for WHO. Our results indicate that the sky brightness at WHO
is seriously influenced by the urban light.
