Computed radiography (CR) imaging has high irradiation tolerance and it is easy to archive CR images along with other image information by Digital Imaging and Communications in Medicine (DICOM) format, and to process them. CR can be used in radiation Quality Control (QC) task and verification of treatment setting-up. In this paper, the role of high-energy CR in radiation oncology is studied. The patients were imaged by CR system and EPID before radiotherapy. All verification images were acquired with 1-2 MU (Monitor Unit) using 6 MV X-rays. QC for a linac was done with film and high-energy CR to collect the data on daily, weekly and monthly basis. The QC included Multileaf Collimators (MLC) calibration and mechanical iso-centre check. CR was also adapted to verify patient position, the film was used to compare with digitally reconstructed radiographs (DRR) and portal image from EPID. Treatment setting-up was verified based on the result of comparison. High quality verification images could be acquired by the CR system. Comparing to EPID, the results showed that the system was suitable for practical use to acquire daily verification images, and it was useful to fulfill part of quality assurance (QA) in radiation oncology. The quality of image acquired by the high-energy CR system is comparable or even better than DRRs and portal images. The final treatment set-up for the patients could be verified more accurately with the CR system.