Abstract: As an ionizing radiation detector, the photo stimulated luminescence response for low energy photons is a fundamental data for imaging plate. The experiment was arranged in the synchrotron radiation center in High Energy Accelerator Research Organization, to get the response data using low energy mono-energetic X-ray. The calculation results were also achieved by Monte-Carlo method, based on a newly developed decay model. The two results show good consistence, which can be used as reference for further research.