Abstract: The evolution characteristics of the reduction process of single iron concentrate particles under high temperature and CO atmospheres were tested in-situ experiment with a high temperature stage microscope. The high-temperature reduction process of the single iron concentrate was recorded via in-situ experiment, and the reduced product (elemental iron) was verified by Raman spectrometer. The results showed that the initial formation time of elemental iron on the particle surface was mainly determined by temperature, and the influence of the gas flow rate was smaller. The initial formation time decreased by about 75% when the reduction temperature increased from 1 100 ℃ to 1 300 ℃, but it hardly changed when the temperature increased from 1 300 ℃ to 1 400 ℃. Nodular structures were found on the surface of iron concentrate particles during the reduction process between 1 100 ℃ and 1 350 ℃, and their sizes increased with the rising reduction temperature. A characteristic number l, which was self-defined as the mean value of the length and width of the particles, increased from 6 μm at 1 100 ℃ to 15 μm at 1 350 ℃. When the reduction temperature was above 1 400 ℃, layered melting products were observed for the iron concentrate particle. The product on the core was reduced iron, the one on the second layer was the root-shaped metal iron with reduced molten ferrous oxide, and the other one on the outer layer was the iron slag containing Al, Ca, Si, and other elements.