The electrochemical character of bilirubin(BR)-M2+(M2+=Cd2+,Cu2+,Zn2+,Ca2+,Fe2+)Langmuir-Blodgett(LB)film modified glassy carbon electrode was investigated,and was compared with that of BR-LB film modified glassy carbon electrode and that of BR and M2+in solution.On BR-M2+-LB film modified glassy carbon electrodes,one anodic peak for BR-M2+ complex was observed at-679~-842mV,and the anodic peak potential of BR shifted towards to ositive from 453 mV to 477~493 mV.BR-M2+(in solution)formed BR-M2+ complex with BR on the BR-LB film modified glassy carbon electrode,at the same time,M2+permeated BR-LB film and occrred electrode reaction.The anodic peak potential of BR-M2+ complex on LB film shifted towards positive with the increasing of stability of biologic metal complex.In BR and M2+ solution,the potentials of two anodic peaks for BR(400 mV and 305 mV)was shifted positive 19~51 mV due to BR-M2+ complex forming,and this potential was effected by the ratio of BR and M2+.Moreover,a pair of symmetrical adsorption peak was appeared at nearly 0 mV,which indicated the hydrophobicity of this complex molecule was stronger than that of BR molecule.