The optical characteristics of electron—trapping (ET) infrared stimulable materials such as CaS:Eu,Sm and CoS:Ce,Sm prepared by sulfurization flux method (SEM) have been measured. The measurements include excitation spectra, stimulation spectra, fluoresoence spectra and infrared stimulated luminesoence, and so on. It is shown that this kind of materials not only behaves infrared up-conversion optical storage and wide response spectrum, but also operate at room temperature and lower cost.