Kinetics of mangenese leaching from pyrolusite of Nhong Shong Hong mine, Chaing Rai province by ferrous chloride in hydrochloric acid was investigated. The variables studied included stirring speed, reaction temperature of 33 degree celcius to 90 degree celcius, amount of ferrous chloride and ferric chloride, hydrochloric acid concentrations of 0.5 to 3.0 M, various particle sizes and percent solid up to 10 percent. The results indicate that the rate of manganese leaching from pyrolusite increases with increased reaction temperature and increased amount of ferrous chloride. The activation energy was measured to be 3.88 KJ/mol (0.92 Kcal/mol). The reaction order with respect to ferrous chloride concentration was determined to be 0.83. Ferric chloride concentration does not affect the rate in this study. With decreased particle size of pyrolusite the rate of leaching increases. But with increased percent solid in the leaching solution, the rate of managanese extraction decreases. The reaction mechanism follows nucleation and grain growth model. This process can be applied to extract manganese from pyrolusite