Herein, carbon nanotube (CNT) supported ruthenium (Ru), iridium (Ir), and copper (Cu) catalysts at 0.1 to 20 wt% metal loading are prepared by the NaBH4 reduction method for glucose electrooxidation reaction (GER). These catalysts are successfully characterized by X-ray diffraction, scanning electron microscope, and N-2 adsorption-desorption measurements. Voltammetric measurements of these catalysts are taken using cyclic voltammetry and chronoamperometry techniques. The crystallite sizes of these catalysts are calculated as 2.53 nm for Ru/CNT, 2.94 nm for Ir/CNT, and 13.06 nm for Cu/CNT by using Scherrer equation. For GER, 10% Ru/CNT, 0.1% Ir/CNT, and 0.5% Cu/CNT catalysts have high current densities as 1.86 mA cm(-2) (160.6 mA mg(-1) Ru), 3.03 mA cm(-2) (23 857.2 mA mg(-1) Ir), and 1.12 mA cm(-2) (1768.8 mA mg(-1) Cu), respectively. These catalysts have also good stability. Results reveal that 10% Ru/CNT, 0.1% Ir/CNT, and 0.5% Cu/CNT catalysts are promising catalysts as direct glucose fuel cell anode catalysts.