A polytyrosine/bismuth modified glassy carbon electrode(p-Tyr/Bi/GC) was firstly prepared by cyclic voltammetry with in situ bismuth plating.The electron transfer impedance and membrane surface morphology on the electrode were characterized by EIS and SEM.The p-Tyr membrane with flower shape evenly distributed on the surface of glassy carbon electrode,which could effectively promote the electron transfer.Taking the square wave anodic stripping voltammetric response of a composite film electrode to Pb2+ as a reference,the optimum preparation conditions for the p-Tyr/Bi/GC electrode and the optimal test medium were investigated.The optimal concentration of tyrosine and number of cyclic voltammetry scan for p-Tyr/GC electrode preparation were 15 mmol·L-1 and 15,respectively.The optimal Bi3+ concentration,pH value and accumulation potential in test medium were 10 μmol·L-1，60,and -120 V,respectively.Under the optimal conditions,the linear equation between the current response of the electrode to Pb2+ and its concentration in the range of 001-016 μmol·L-1 was Ip(μA)=0503 2+5468c(μmol·L-1)(r=0994 7),with a detection limit(3S/k) of 08 nmol·L-1.With high sensitivity,good stability and strong anti interference ability,the p-Tyr/Bi/GC electrode was successfully used for the determination of lead in tea samples with recoveries of 906%-963%and relative standard deviations not more than 39%.