In the present work graphene oxide GO prepared by chemical exifliation of graphite using Hummer’s method. A facile and green synthesis of ZnO-rGO nanocomposite was performed via Alovera plant extract. The characterization tools (XRD-FTIR- FESEM-TEM- AFM) proved the formation of single phase of ZnO-rGO nanocomposite. Since the environmental contamination caused by Cd(II) ion is a world issue as it has a harmful effect especially on the human health and environment. Subsequently, our goal in this work is to find an accurate method for detection and adsorption of toxic Cd(II). ZnO and ZnO-rGO nanocomposites are prepared for removing Cd(II) and on behalf of increasing its removal efficiency, GO is added. The results showed a great improvement in removal efficiency reached up to 90% at pH 6 after 90 min. the structure and surface of prepared samples studied through XRD, FTIR, FESEM and AFM.