The project was designed according to the theory of biological fixation and removal of manganese. The process included weak aeration and one filtration. Inoculating the aboriginal manganese removal bacteria from raw water, after 2～3 months culture, the filter obtained the strong manganese removal ability. Under the condition of usual filtrating rate, manganese in treated water was 0.05 mg/L,and T_Fe was trace which were superior to the national standard although the manganese in raw water was 1～3 mg/L and T_Fe was 0.1～0.5 mg/L. The quality of the treated water was stable and met the industry requirement. This theory solved the difficulty of manganese removal over the past harf of century and built the fist biological removal of iron and manganese water plant in the world.