A polyether-based copolymer of acrylic acid-allylpolyethoxy maleic carboxylate (AA-APEY) was prepared by copolymerization of allylpolyethoxy carboxylate (APEY) and acrylic acid (AA) at different mole ratios. The main aim of this work was to investigate the influence of AA-to-APEY mole ratios on the copolymer properties and scale inhibition performance for gypsum. The synthesized copolymer was characterized by Fourier-transform infrared (FT-IR) and further conformed by 1H NMR. The effect of AA-APEY on controlling calcium sulfate deposits was studied through static scale inhibition tests under standard solution conditions. And the result was compared with that of other polycarboxylates, which are similar to AA-APEY in structure. Scanning electronic microscopy (SEM), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) analysis were carried out to study the morphology and structure changes of calcium sulfate crystals in the presence of AA-APEY. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40193.