Abstract: A preliminary investigation has been performed on the classification and content of microorganisms from the loess section at the Gongwang Ridge in Lantian, Shanxi Province, and on their evolution since 1.2Ma. It is shown that the loess and paleosol that have formed ever since the late stage of Early Pleistocene are characterized by abundant Bacillus, minor Penicillium and no Actinomycetes. The content of microorganisms decreases regularly up the section and is unexceptionally higher in the paleosol than that in the loess. Most of the bacteria are found in the horizons close to and below the boundary between the Early and Middle Pleistocene series.