Abstract: Reaction kinetics of superfine α-FeOOH prepared with air oxidation process in trace alkali medium is studied. The effect of primary sub-ferrous ion concentraction (C₀), reaction temperature (T), stirring rate (n), partial pressure of oxygen (po₂) and alkali/ferrous ratio (R) on reaction rate is analyzed and equation of reaction kinetics during nuclear forming period has been established with zero stage reaction for both Fe(Ⅱ) and partial pressure of oxygen and apparent activation energy of reaction is 12.25 kJ/mol.