Abstract: Bioleaching experiments on the open stripe nickel ore in Jinchuan Mine of China were carried out. It is demonstrated that the leaching of nickel is combined bio-direct action with bio-indirect action. Thiobacillus ferrooxidans (TF) chemistry behavior difference between TF living in the culture medium and that living on the surface of the ore is based on the protein membrane which grows on the surface of TF. The Ni leaching rate and the oxidative activity of TF are influenced by the growth rate of TF adhered on the solid phase and free in the liquid phase, mineral mass density, Fe³⁺ concentration and pH consistency. Add on-ferric ion can interfere in the bacteria oxidative and inhibit the leaching of Ni, which lead to the formation of sediment on the surface of the mineral and reduce the leaching rate of Ni.