  Compact disc galaxies (CDGs) with high surface brightness were identified in
the Sloan Digital Sky Survey (SDSS) data. We determined the surface profiles of
the CDGs and compared them to those of normal-sized disk galaxies (NDGs). The
CDGs have higher central brightness and older stellar age than the NDGs.
Furthermore, the brightness profiles of the CDGs fit a S{\'e}rsic model with $n
\approx 2.11$ and have a zero $g^{\prime}-r^{\prime}$ color gradient on
average. By contrast, the NDGs fit an exponential profile and have a negative
color gradient on average. These results indicate that the structure and
stellar population of the CDGs and NDGs differ. We suggest that the CDGs are
ancient galaxies in the quenching phase following the initial central
starburst.
