Ca1-x-ySO4:Eux,Dyy (0 < x < 0.04, 0 < y < 0.04) phosphors were prepared and characterized by XRD. The samples were well crystalline and exhibit orthorhombic structure. The phosphor Ca0.99SO4:Eu0.005Dy0.005 was found having highest TL intensity. The phosphor was annealed at different temperatures. All the TL glow curves have one prominent peak at 420K. TL intensity for this peak was found decreasing when the phosphor was annealed at a particular temperature for different durations.