The results are presented with emphasis on the relative dose-enhancement factor for complementary metal-oxide semiconductor (CMOS) devices irradiated by steady state and transient pulsed X-rays. With the help of experimental study, sensitive parameter threshold voltage as a function of irradiation dose was obtained. So the equivalent relation of total dose damage is eslablished by comparing the response of devices irradiated by 60Co γ-rays and X-rays. By employing the X-ray transient pulsed sources, the research of X-rays transient upset enhancement effects is carried out using bi-laminate structure. Upset enhancement factor of X-rays are measured. These methods are provided for X-ray radiation hardening technology an effective evaluation method.