Abstarct: In this Thesis the potential of alternative oxidants for oxidation of refractory gold ore with emphasis on process mechanism was investigated, case study Zar-Shooran Gold Mine. The recovery of gold in Zar-Shooran Gold plant is done with ammonia and lime-baxsed salt for oxidation, but gold recovery is low. Therefore, hydrogen peroxide and potassium hydroxide oxidants were used to sulfide minerals oxidizing. Hydrogen peroxide and potassium hydroxide oxidants were used for oxidation the refractory gold ore with aeration, without aeration, without catalyst and with Acetyl Acetonat Dioxide Molybdenum catalyst. Firstly, mineralogical studies consist of glue sections, EPMA, XRD, XRF, and ICP of Zar-Shooran gold ore were carried out. Thus, the main minerals that have reaction and consumed cyanide were determined and Pyrite, Realgar, Orpiment, Arsenopyrite and Stibnite minerals were characterized. Then, the effect of pH, oxidizing agent dosage, temperature, reaction time and aeration rate parameters on the rate of oxidation of five sulfide minerals was investigated. The optimum pH for hydrogen peroxide and potassium hydroxide was obtained at 12.80 and 10, respectively. After optimizing the parameters, the highest recovery rate of hydrogen peroxide with aeration was obtained 98.86%. Finally, the kinetic modeling and process activation energy for both oxidant was calculate, the highest and lowest kinetics rates for hydrogen peroxide and potassium hydroxide are 0.00006 and 0.00005, respectively. The results indicate that the catalyst decrease the reaction time more than 4 hours.