Abstract: The sedimentary-metamorphic manganese deposit is an important type of mineral deposit in China and abroad. The Hongshuihe iorn-manganese deposit is the important discovery for Iorn-Manganese ore prospecting in Eastern Kunlun recently. Based on the study about the geological background and the deposit characteristics of Hongshuihe iorn-manganese deposit, the main achievements are obtained as follows. This deposit is located in Jixianian Langyashan Formation, and the ore-body is controlled by stratigraphic position and lithology. It is formed in anoxic environment through the debris deposition, hydrothermal sedimentary, metamorphic and supergene oxidation, which belongs to sedimentary-metamorphic deposit. The discovery of Hongshuihe deposit not only can actuate the exploration and research works of iron-manganese ore in Qinghai Province, but also can expand the prospecting area of Mesoproterozoic manganese deposit.