Abstract: With the development of a high efficiency concave grating monochromator, a pulsed Xray facility for wavelength resolved decay time measurement is made upon the basis of original ultra short pulsed X-ray facility. The wavelength resolution and time resolution of the facility are in the scale of nanometer and subnanosecond, respectively. The study of BaF₂ shows that the equipment can be applied to measure decay time of different fluorescent components from scintillator quite well. The counting rate for such measurement is only two orders of magnitude lower than for decay time spectra measurement without the monochromator. In addition, the wavelength resolved fluorescent lifetime of CeF₃ scintillation crystal is studied by the facility.