Abstract: Gallium forming a chalete compound with morin at pH 5 adsorbs on hanging mercury drop electrode and gives a sensitive reducing wave when scanned cathodically. In this paper, the optimum conditions were sought, and the interference of co-existing ions is investigated. Its peak current is proportional to the concentration of gallium in the range of 1~120 ppb; the limit of detection is 0.3ppb. The proposed procedure is applied to the determination of galliumin in steels, iron, ores and slags in Pan Zhi Hui Steel and Iron Plant.