A simple hydrothermal synthesis of nickel hydroxide–ordered mesoporous carbons nanocomposites (Ni(OH)2–OMCs) is proposed for the first time. The characterization of the new material shows that, after anchoring Ni(OH)2 nanoparticles on the mesoporous, ordered mesostructure of the nanocomposites remain intact and Ni(OH)2 is electrochemically accessible. The performance of Ni(OH)2–OMCs is compared to OMCs and the properties of the new material are found to be improved. A sensor for sensitive detection of underivatized glycine has been developed based on Ni(OH)2–OMCs modified glass carbon (Ni(OH)2–OMCs/GC) electrode. The linear response of glycine measurement was up to about 3.2mM with a high sensitivity of 10.5μAmM−1 for the Ni(OH)2–OMCs/GC electrode. The detection limits was estimated to be 0.26μM (S/N=3). Then ethanol was selected as another marked molecule, a nonenzymatic amperometric sensor of ethanol based on the Ni(OH)2–OMCs nanocomposites is also constructed. The linear response of ethanol measurement was up to about 80mM with a sensitivity of 0.65μAmM−1. The detection limits was estimated to be 4.77μM (S/N=3).