Y1.97-xTi0.03CdxO2S (0≤x≤0.06) phosphors with long afterglow were synthesized by solid-state reaction. The photoluminescence spectra, decay curves, thermoluminescnece spectra and Chromaticity coordinate curves were investigated. Results showed that the luminescence and afterglow intensity of Y1.97-xTi0.03CdxO2S (0≤x≤0.06) reduced gradually with increasing Cd2+ ion content while the shape and position of emission peak remain unchanged. The Chromaticity coordinate of present phosphor keeps at (0.5497,0.4415). Furthermore, based on the results of thermoluminescence curves of Ti, Cd single doped and co-doped Y2O2S phosphors, the doped Cd ion reduces the inherent trap depth of Ti single doped Y2O2S:Ti, and induces simultaneously a new trap level in Y2O2S:Ti,Cd phosphor. Thus, it was proposed that the introduced new structure defect by Cd2+ ions should be responsible for the reducing luminescence and afterglow property.