  We report on the next-to-leading order(NLO) QCD computation of top-quark pair
production in association with a photon at the Fermilab Tevatron RUN II and
CERN Large Hadron Collider(LHC). We describe the impact of the complete NLO QCD
radiative corrections to this process, and provide the predictions of the
leading order(LO) and NLO integrated cross sections, distributions of the
transverse momenta of top-quark and photon for the LHC and Tevatron, and the LO
and NLO forward-backward top-quark charge asymmetries for the Tevatron. We
investigate the dependence of the LO and NLO cross sections on the
renormalization/factorization scale, and find the scale dependence of the LO
cross section is obviously improved by the NLO QCD corrections. The K-factor of
the NLO QCD correction is $0.977(1.524)$ for the Tevatron(LHC).
