The Fenton system generates reactive species with high oxidation potential such as hydroxyl radicals (HO(•)) or ferryl via the reaction between Fe (II) and H₂O₂. However, a number of drawbacks limit its widespread application including the accumulation of Fe (III) and the narrow pH range limits, etc. The aim of this study is to propose a much more efficient Fenton-HA system which is characterized by combining Fenton system with hydroxylamine (NH₂OH), a common reducing agent, to relieve the aforementioned drawbacks, with benzoic acid (BA) as the probe reagent. The presence of NH₂OH in Fenton's reagent accelerated the Fe (III)/Fe (II) redox cycles, leading to relatively steady Fe (II) recovery, thus, increased the pseudo first-order reaction rates and expanded the effective pH range up to 5.7. The HO(•) mechanism was confirmed to be dominating in the Fenton-HA system, and the generation of HO(•) was much faster and the amount of HO(•) formed was higher than that in the classical Fenton system. Furthermore, the major end products of NH₂OH in Fenton-HA system were supposed to be NO₃(-) and N₂O.