MgSO4: Dy, MgSO4: Tm and MgSO4: Dy,Mn thermoluminescence (TL) phosphors have been prepared and their emission spectra were measured using a linear heater and optical multichannel analyzer. Emission bands at about 480, 580 and 660 nm of MgSO4 doped with Dy were observed in three dimension (3D) glow curve. Emission bands about 360, 460, and 660 nm were observed in a 3D glow curve of MgSO4 doped with Tm. The emission spectra of MgSO4:Dy and MgSO4:Tm are attributed to the characteristic emission wavelengths from transitions of Dy3+ and Tm3+respectively. The results show that the structures of traps in matrix materials determine the activation energy distribution and dopant energy levels of rare earth ions are related with the emission spectrum wavelengths of sulfate phosphors. The intensities of the glow peaks in both bands at about 480 and 580 nm in MgSO4 doped Dy and Mn were dramatically reduced in comparison with that of MgSO4 doped Dy except above 3008C. It means that the trapping structures of MgSO4 : Dy phosphor has greatly been altered by the co-dopant Mn but no change is observed in wavelengths of the emission spectra.