A novel green scale inhibitor, polyaspartic acid/urea graft copolymer (PASP/Urea), was synthesized by polysuccinimide (PSI) and urea. PASP/Urea was a non-toxic, non-phosphorus, biodegradable acylamino copolymer. The structure of PASP/Urea was characterized by Fourier transform infrared spectroscopy (IR), H-1 nuclear magnetic resonance (H-1 NMR) and gel permeation chromatography (GPC) analysis. Its scale inhibition performance was estimated with static scale inhibition methods. The influence of PASP/Urea on formation of CaCO3, CaSO4 and Ca-3(PO4)(2) was investigated using scanning electronic microscopy (SEM). The PASP/Urea exhibited more excellent scale inhibition property against CaCO3, CaSO4 and Ca-3(PO4)(2) than the PASP and the comprehensive scale inhibition property of PASP/Urea is much better than the property of PASP. The scale inhibition efficiency of PASP/Urea against CaCO3 was 93% when the dosage of PASP/Urea was 10 mg/L. The inhibition efficiency against CaSO4 increased to 97% in the PASP/Urea concentration of 4 mg/L. The inhibition efficiency against Ca-3(PO4)(2) reached up to 100% in the concentration of 12 mg/L. The results of SEM indicated that the scale crystals became irregular and distorted and the formation of scales was inhibited when the PASP/Urea was added. (C) 2016 Elsevier B.V. All rights reserved.