  We show that the asymmetries in the nuclear resonance fluorescence processes
with a circular polarized photon beam may be used as a tool for studying the
parity non-conservation (PNC) in nuclei. The PNC asymmetry measurements both in
exciting the parity doublet states and in exciting the discrete states near the
ground states with parity mixing are discussed. We derived the formulae needed
for measuring the PNC asymmetries.
