In order to lower the limit of detection of glucose, a peroxidase-like artificial enzyme with elevated catalysis capacity has been achieved. Fe3O4-doped MnO2 microspheres were fabricated through a two-step hydrothermal method for this purpose. TEM revealed that down-sized Fe3O4 nanoparticles were dispersed throughout the urchin-like MnO2 burrs. An additional XRD peak beyond Fe3O4 and MnO2 nanoparticles was observed, indicating a dislocation structure was formed. The defect in structure as well as the synergistic effect would allow extra enzyme ability. Based on the steady-state kinetic analyses and Michaelis-Menten model, the Michaelis-Menten constants (K-m and v(max)) were figured out. The results showed that the Fe3O4-MnO2 composite has elevated affinity toward the substrate TMB and H2O2. The limit of detection for glucose was estimated to be 0.75 mu mol L-1 based on the Fe3O4-MnO2 composite artificial enzyme. The superparamagnetic properties endowed the material easy separation. The composite of this structure will provide a highly sensitive candidate method for accurate detection of glucose.