Abstract: The authors adopted subjective and objective methods for measuring high-contrast resolution (HCR) of CT and explored the parameters in relation to HCR. With Catphan500 and a self-prepared experimental phantom, the two CT sets were tested for HCR with varied slice thickness and kernels. The subjective assessment of the images was carried out by visual detection of HCR, and objective assessment was performed by calculations. Each of the methods has its advantages and limitations, and many factors may affect the HCR of CT.