Qaidam Basin is the largest intermont basin in the northeast of Qinghai-Tibet Plateau. It's continuous sedimentary sequence provides a good example for studying the global climate evolution since the Cenozoic. Our research mainly focus on the paleosols developed at the bottom of Luluhe Formation, Dahonggou section, Qaidam Basin. The stratigraphic tendencies are about 200° ~220°, and dip angles are about 25° ~ 40°. The total thickness of the paleosol layers were calculated to be about 126 m(the length of Lulehe Formation is about 460 m, and the paleosols were sampled from ca. 50 m to 176 m). The lithology is dominated by conglomerate, gravel, sandstone, siltstone and mudstone, with some thin laminated mudstone and paste. And the deposits are alluvial fan facies. According to the previous studying, we speculate the time span of paleosols of Luluhe Formation is during 52 ~ 50 Ma. It is during the period of Early Eocene Climatic Opitmum(EECO). Hematite (Hm) and goethite(Gt) are two common weathering products in paleosols. Their sensitivity to the environment can help us to understand the humidity of soil and pedogenesis as the paleo-climate changing. We use the diffuse reflectance spectroscopy (DRS) to quantify the iron-oxide in paleosols of Lulehe Formation. To collecte fresh samples, 19 channels were digged manually. Each sample weighs about 300~500 g, and the total number of samples is 228. The results showed the existence of hematite and goethite clearly in the paleosols. The content of hematite was about 0.09 ~ 17.16 g/kg, and the content of the goethite was approximately 0.13 ~ 24.6 g/kg. The goethite is higher than hematite in many samples (Gt/Hm fluctuated between 0.04 to 34.34, with an average of 2.18),and the data fluctuated sometimes. During the early stage of EECO, the mean annual precipitation(MAP) was high with the average of Gt/Hm is 3.06. The data fluctuated sometimes, which indicates a warmer and wetter, with seasonally humid and dry climate. The MAP goes down between middle stage of EECO, meanwhile the average of Gt/Hm come down to 1.75, indicating a dryer climate. And during the late stage of EECO, the MAP is higher than before and the average of Gt/Hm is 1.80, indicating a warmer and wetter climate again. We also correlated the early stage of the paleosols to the peak stage of EECO. The climatic features of paleosols is the response to the global climatic warming events.