Abstract: Metal-organic framework nanofibers were used as horseradish peroxidase immobilization materials,chitosan was used as a film-forming agent to prepare an electrochemical biosensor(HRP-MONFs/Chit/GCE)for the detection of hydrogen peroxide residues in foods by drop coating.Drop cast method was used to fabricate the electrochemical biosensor. The fabricated biosensor was evaluated in terms of electrochemical properties including electrochemical impedance(EIS)and cyclic voltammetry(CV),and the preparation method and detection conditions were optimized. Results showed that,HRP-MONFs/Chit/GCE exhibited a good linear relationship(R²=0.999)in the range of hydrogen peroxide concentration of 12.5~675 μmol/L,and the minimum detection limit was 0.97 mol/L. HRP-MONFs/Chit/GCE had good storage stability,which was able to retain 94% of its orginal response during the 24 days storage test at 4 ℃. The fabricated biosensorwas successfully employed for detection of trace level of hydrogen peroxide in both solid and liquid food.