With sodium sulfide as a reducing reagent and a precipitant in acidic condition, the removal of arsenic (As (III) and As (V)) from industrial 1-Hydroxyethylidenediphosphonic acid (HEDPA) is carried out by a reduction-precipitation method. The purpose is to obtain the effect the quantity of the sodium sulfide, pH value of the solution factors, temperature, time, and mixing speed on de-arsenic. The result shows that the optimal temperature, pH, mole ratio of sodium sulfide to arsenic species and agitation rate are 50℃, 0.5, 4:1 and 90rpm, respectively. After 2h under the selected conditions, the corresponding concentration of arsenic species in HEDPA and efficiency of arsenic removal are 0.28 mg•L-1 and 99.3%, respectively. HEDPA treated by the procedure can serve as detergent & cosmetics additives and raw materials for synthesis of drugs.