Luminescence spectroscopy measurements were performed in a one-dimensional halogen-bridged transition-metal compound [NiBr(chxn)(2)]Br-2 (chxn: 1R,2R-cyclohexanediamine) and its mixed-metal compound [Ni1-xPdxBr(chxn)(2)]Br-2 with x = 0.005, 0.05, 0.33. The broad peaks were observed at 1.3) and 1.4 eV for [NiBr(chxn)(2)]Br-2, which are attributed to a relaxation of LMCT exciton state and a hot luminescence, respectively. No Stokes shift of the luminescence at 1.3 eV was observed, which shows the electron-lattice interaction (S) is weak in this system. From the temperature dependence of luminescence spectra, it was clarified that the relaxation process is continuously changed from luminescence to thermal relaxation. The luminescence peak at 1.3 eV is remarkably quenched with increase of x for [Ni1-xPdxBr(chxn)(2)]Br-2, implying that the LMCT exciton is trapped to in-gap states caused by doped Pd3+.