  We present the analysis of archival data from ROSAT and ASCA of a
serendipitous source PKS 2316-423. According to its featureless non-thermal
radio/optical continuum, the object has been assumed as a BL Lac candidate in
the literature. It was evident variable over the multiple X-ray observations.
Specially, a variable high-energy tail of the synchrotron radiation is
revealed. X-ray spectral analysis provided further evidence of its
synchrotron-nature broad-band spectrum with steep and down-curved shape in the
range of 0.1-10 keV. Further SED analysis suggest that it is a very low
luminosity ``intermediate'' or high energy peaked BL Lac object. Given the
unusual low luminosity, the further studies of PKS 2316-423 might give clues on
the evolution properties of BL Lacs.
