Abstract: AIM: To sdudy the electrochemical behavior of bleomycin at Ni/GC electrode and its application. METHODS: With Ni/GC ion implantation modified electrode as working electrode, the behavior of bleomycin was studied by voltammetry in 0.1 mol.L^-1 HAc-NaAc (pH 4.62) buffer solution. RESULTS: A sensitive reductive peak of bleomycin was obtained by linear sweep voltammetry. The peak potential was -1.15 V (vs.SCE). The peak current was proportional to the concentration of bleomycin over the range of 1.0×10^-6～1.4×10^-5 mol.L^-1. The limit of detection was 8.0×10^-7 mol.L^-1. The behavior of the reduction peak was studied and applied to the determination of bleomycin in urine. CONCLUSION: The reduction process was irreversible. The element composition, atomicity form and depth of distribution at the surface of Ni/GC electrode were determined by Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy(XPS). The catalysis behavior at Ni/GC ion implantation modified electrode was also studied.