Abstract: A horseradish peroxidase (HRP) modified electrode (HRP/Au-Gemini/GC) was fabricated by immobilized on the Au-Gemini nanocomposite modified glassy carbon (GC) electrode. The direct electrochemistry of HRP was investigated on the HRP/AuGemini/GC electrode, and the modified electrode was applied to study the electrocatalytic reduction of H2O2．The results showed that the direct electrochemistry of HRP can be facilely achieved on HRP/Au-Gemini/GC and a couple of quasi-reversible redox peaks of HRP were observed at about -0.236 V(Epa) and -0.273 V(Epc). The HRP/Au-Gemini/GC electrode displayed good electrocatalytic reduction of hydrogen peroxide. The apparent MichaelisMenton (Km) was 2.0×10-5 mol/L and the linear range was 1.0-7.0 μmol/L. The study provides an efficient strategy to achieve the direct electron transfer of redox enzymes and fabrication of biosensors.