In the experiments using the X-ray free-electron laser (XFEL), variety of the x-ray detectors will be required to explore every novel possiblity. Toward XFEL utilization, evaluation and optimization of the CCD detectors, which are under development by RIGAKU, will be carried out at the SPring-8 endstations. In addition, conceptual design for the high speed data acquisition system will be carried out in order to realize the next- generation CCD detector for XFEL.