Abstract: Au［C12min］［Br］ nanocomposite was synthesized by UV photocatalysis in ion liquid, ［C12min］［Br］. Hb/Au［C12min］［Br］/GC modified electrode was fabricated by Hb immobilized on the Au［C12min］［Br］ modified glassy carbon(GC) electrode. The electrochemical property showed that the quasireversible eletrode reaction happened on Hb/Au［C12min］［Br］/GC electrode. The anodic peak potential (Epa) and cathodic peak potential (Epc) were located at -0.253 V and -0.335 V, respectively. The Au［C12min］［Br］ nanocomposite accelerated the direct electron transfer of Hb, and showed high electrochemical activity. The Hb/Au［C12min］［Br］/GC electrode has good electrocatalytic activity for H2O2, which should be valuable for further study on H2O2 biosensors.