Novel liquid crystalline malonic ester monomer was synthesized from malonyl dichloride and disperse red 1, a photoresponsive group. The monomer was polymerized with 1,6-dibromohexane, 1,8-dibromooctane, 1,10-dibromo-decane, 1,12-dibromododecane, alpha,alpha'-dibromo-p-xylene, alpha,alpha'-dibromo-m-xylene, or alpha,alpha'-dibromo-o-xylene in the presence of sodium hydride to give seven kinds of novel poly(malonic esters) with two symmetrical photoresponsive groups in the side chain. The resulting polymer films were found to be excellent as reversible optical information recording media for data storage and retrieval through a trans-cis isomerization of azobenzene group by Ar laser irradiation. The sensitivity of data recording was dependent not only on the thickness of the polymeric thin film but also on the intensity of laser beam. (C) 2002 Elsevier Science B.V. All rights reserved.