In this work, erbium-doped calcium aluminum silicate (CAS) glass has been synthesized by solid-state reaction. Intense emission at 1534 nm, corresponding to the I-4(13/2) --> I-4(15/2) transition of the Er3+ ion, was observed upon both 488 nm Ar+ laser and 978 mn diode laser excitations at room temperature. The luminescence mechanisms in the glass are discussed. These results indicate this glass is a promising laser material with its high chemical durability and thermal stability.