Abstract: Bismuth film modified glassy carbon electrode was prepared by electrochemical deposition of Bi3+-ion on glassy carbon electrode (GCE). In the determination of Ga3+-ion, the test solution in (CH2)6N4-HCl buffer solution of pH 5.4 was prereduced for 40 s at -1.30 V, Ga3+-ion was then stripped from the electrode by differential pulse stripping voltammetery, scanning in the range from -1.30 to -0.50 V. Oxidation peak potential of Ga3+-ion was observed at -1.01 V, at where linear relationship between values of peak current of Ga3+-ion and its concentration was obtained in the range of 0.002 8-0.21 μg·L-1. Detection limit (3S/N) of the method found was 0.7 ng·L-1. The proposed method has been used in the determination of gallium in aluminum foil, giving values of recovery found by standard addition method in the range of 98.2%-103.8%.