Pacific Ocean manganese nodule samples were leached with dilute sulfuric acid in the presence of phenol type aromatic reducing agents. Six phenols, including hydroxybenzene, o-dihydroxybenzene, m-dihydroxybenzene, p-dihydroxybenzene, o-trihydroxybenzene and m-trihydroxybenzene. were rested. The results indicated that all the rested phenols were effective reducing agents that significantly increased the extraction of Mn, Cu, Ni, Co from the nodules. At a dosage of 0.25 similar to 0.4 grams of the reducing agents and 0.925 grams of H2SO4 per gram of nodules, over or nearly 95% of the Mn, Cu, Ni and Co could be extracted in IO similar to 20 minutes from art aqueous slurry containing about 20% manganese nodule, under ambient temperature and pressure. In the absence of the reducing agents, the extraction of Cu was about 65% and that of Mn, Ni and Co was below 20%. ESCA, TLC and UV/VIS spectroscopic analyses indicated that the Mn in the nodules was reduced in the presence of phenols in the acid medium, while the phenols could be oxidized to p-benzoquinone.