The carbonate content in the stratigraphy of Loess and inland lakes is a sensitive indicator of climatic changes. 3267 samples in total were collected at 2.5 cm intervals from an 80 m thick lacustrine deposits, spanning 2.35 Ma, in the Dongshanding section of Linxia Basin. All the samples were analyzed by using a standard Bascomb calcimeter. The variation of carbonate contents shows that there exist two obvious cold-humid events in the Early Pleistocene at about 2.28 Ma and 1 .8 Ma to 1 .75 Ma, respectively. During these two periods the climate was cold or cool. The climatic change was dominated by an obvious 41 000a periodicity. The results also indicate that in the early period of the Quaternary, the monsoon climate had been established but was not very stable. The carbonate content in the stratigraphy of Loess and inland lakes is a sensitive indicator of climatic changes. 3267 samples in total were collected at 2.5 cm intervals from an 80 m thick lacustrine deposits, spanning 2.35 Ma, in the Dongshanding section of Linxia Basin. All the samples were analyzed by using a standard Bascomb calcimeter. The variation of carbonate contents shows that there exist two significant cold-humid events in the Early Pleistocene at about 2.28 Ma and 1.8 Ma to 1.75 Ma, respectively. During these two periods the climate was cold or cool. The climatic change was dominated by an obvious 41 000a periodicity. The results also indicate that in the early period of the Quaternary, the monsoon climate had been established but was not very stable.