Jianzha Basin is located in the northeastern Tibetan Plateau and situated in a climatically sensitive area-at the transition zone between the monsoon region to the east and the arid region to the west; its location, together with its thick, continuous sequence of Cenozoic sediments, makes it well be suited to monitoring changes in Late Cenozoic climate. Jiarang section is located in the left bank of the Jiarang river, near the Jiarang village of Jianzha County, Qinghai Province, and its geographical coordinates are 35°57'43.1"N,101°58'24.1"E,2200 m a.s.l. Based on the field observation and the study of sedimentary facies, the 361-m-thick sediments sequences of the Jiarang section mainly consist of clastic material of fluviolacustrine and eolian origin,with loess-like silt or clay comprising about two-thirds of the entire section. The samples of this experiment was sampled at 20 cm intervals, and a total of 1781 samples were collected. The magnetostratigraphic results show that the sediments have recorded a continuous geomagnetic polarity sequence from C5r.3r to C3r,spanning the interval from 11.8~5.8 Ma in the Late Miocene. By the experiments analysis of the carbonate minerals in sedimentary section, the content of calcite and the low frequency magnetic susceptibility change were analyzed to reveal the paleoclimatic information from the deposits during 11.8~5.8 Ma, which the paleoclimate change can be divided into four stages. Stage I: 11.8 ~ 9.8 Ma, dry and cold climate; Stage Ⅱ:9.80~8.57 Ma, warm and humid climate; Stage Ⅲ: 8.57~6.15 Ma, warm and humid climate and Stage IV: 6.15 ~ 5.80 Ma, dry and cold climate. The content of calcite and the magnetic susceptibility change dramatically before ca. 8.57 Ma reflect intensified precipitation which resulted from the growth of the NETP. From ca. 8.57 Ma to ca. 7.2 Ma, the East Asian summer monsoon was impacted by global cooling and ice build-up in the Northern Hemisphere in addition to the uplift of the Tibetan Plateau in the Late Miocene. From ca.10 Ma to ca. 8 Ma, the content of dolomite increases significantly, which probably caused by the rapid uplifting and deforming of the Tibetan Plateau in this stage.