The fluorescence excitation and emission spectrum of electron trapping material Eu,Sm∶CaS at room temperature are investigated. The excitation spectrum consists of four emission bands, which are assigened to 4f6→4f55d transition of Eu2+ ion and fundamental absorption of CaS. The fluorescence emission spectrum excited at visible light consists of one strongest broaden emission band and two weakest narrow emission bands. While in the spectrum excited at ultraviolet light, not only the three emission bands but also seven stronger narrow emission bands are observed, which are assigned to 4f65d→4f7 transision of Eu2+, f→f transition of Sm3+, f→f transision of Eu3+ respectively. It is found that the fluorescence emission strength of Eu2+ ion is apparent stronger than that of Sm3+ as the activator concentrations are proper.