A rapid method for determination of boron in acidic medium by using fluoborate ion-selective electrode was studied. This method was based on converting of boron iato tetrafluoborate ion with hydrofluoric acid and then the concentration of tetrafluoborate was measured with fluoborate ion-selective electrode. Macro amounts of iron, aluminum, calcium, magnesium and manganese etc did not cause interference. The recoveries of boron were 95-103%