The midPleistocene climate transition (MPT) is a period in geologic history marked by a gradual change in climate periodicity from 40 ka to 100 ka at approximately 0.9 Ma BP, around the marine isotope stages (MIS) 22/23 boundary. Here we present a high resolution record (~290 a sampling interval) of foraminiferal stable isotopes during 0.8~1.0 Ma at this site. Our data indicated that the Asian monsoon strengthened after the MPT, resulting a deepened thermocline. The depth of the thermocline (DOT) and the nutrientcline were found to be deeper during the glacials than in interglacials before the MPR. After the MPR, the DOT and the nutrientcline became deeper in interglacials than in glacial periods. On the orbital time scale, the surface water change synchronized with the bottom water change. However, on the millennial time scale, spectral analysis of foraminiferal oxygen and carbon isotope data revealed dominant periodicities at ~0.8 ka and ~1.4 ka, indicating the climatic instability during the MPT. Furthermore, the amplitude changes of the millennialscale climate instability were amplified after 0.9 Ma. Most of the strong cyclic signals occurred during the interglacials during the MPT, which is different from the millennial climatic instability during the later Pleistocene. Therefore, our isotopic results confirm the previous conclusion of color reflectance (CR) analysis at this site.