Abstract: In order to obtain the response of imaging plates (IPs) for X/γ-ray with middle/high energy through experiments，the sensitivity of IPs for incident X/γ-ray in the range from 40 keV to 1.33 MeV was studied based on X-ray device and radiation source ¹³⁷Cs and ⁶⁰Co. The sensitivity of IPs was studied and simulated by physical model and Monte Carlo method, and the results are in good agreement with the experimental results. Besides, based on the deposition efficiency of X/γ-ray in the IPs photosensitive layer, the sensitivity of IPs for absorbed X/γ-ray was studied, and the theoretical calculation result is in good agreement with the experimental result. The result of this study provides a data support and technical basis for the application of IPs in X/γ-ray with middle/high energy measurement.