  We present the optical reflectance and conductivity spectra for non-oxide
antiperovskite superconductor $MgCNi_{3}$ at different temperatures. The
reflectance drops gradually over a large energy scale up to 33,000 cm$^{-1}$,
with the presence of several wiggles. The reflectance has slight temperature
dependence at low frequency but becomes temperature independent at high
frequency. The optical conductivity shows a Drude response at low frequencies
and four broad absorption features in the frequency range from 600 $cm^{-1}$ to
33,000 $cm^{-1}$. We illustrate that those features can be well understood from
the intra- and interband transitions between different components of Ni 3d
bands which are hybridized with C 2p bands. There is a good agreement between
our experimental data and the first-principle band structure calculations.
