Three kinds of cyclic anhydrides, which stand for aliphatic anhydride, aromatic anhydride, and anhydride containing double bond: succinic anhydride, phthalic anhydride, and maleic anhydride have been copolymerized with propylene oxide and low molecular weight polyoxypropylenediol via ring-opening copolymerization initiator by double metal cyanide complex catalyst to synthesis a series of polyetherester (PEE) polyols. The structure of the obtained copolymers was confirmed by several analysis methods. Three kinds of polyetherester polyurethane (PEEPU) were thus synthesized by polymerization of as-synthesized PEE polyol with 4,4'-diphenylmethane diisocyanate. The mechanical properties of the obtained PEEPU were tested. The results showed that the mechanical properties of three polyurethanes are different based on their structure and composition. The inducing of the rigid phenyl group in the soft segment can improve the mechanical strength remarkably. The influences of ester content in soft segment and the hard segment content on the mechanical properties of PEEPU were studied. (c) 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 417-424, 2007