The Southern Ocean CaCO3 deposition not only records the processes of the biological pump modulating atmospheric CO2, but also the changes in Southern Ocean surface frontal system and the structure of deep ocean circulation. CaCO3% and its mass accumulation rate (MAR) changes at Tasman Sea site ODP 1170 during the past 2 Ma indicate a “Atlantic-style” feature with low CaCO3% during glacials and high during interglacials. Three sedimentary regimes are presented roughly bounded by MIS 34/35 (1.15 Ma BP) and MIS 14/15 (0.55 Ma BP); and the MAR-CaCO3 represents five phases fluctuation. Cross-spectrum and wavelet analysis of CaCO3% and orbital parameters ETP, and benthic δ18O records show clear Mid-Pleistocene Transition (MPT) pattern of the main cyclicity transits from 40 ka to 100 ka, from 1.15 to 0.55 Ma BP. The changes in CaCO3 deposition are closely related to the changes in Southern Westerlies and Antarctic Circumpolar Current（ACC） frontal system, and synchronous with the MPT. During the MPT, the rapid migration of the Southern Westerlies and ACC frontal system resulted in the dilution effect of siliceous deposition and terrigeneous input to the CaCO3 deposition. The MAR-CaCO3 variability is related to the changes in deepwater structure and its chemical properties. At 1.5~0.85 Ma BP, Southern Ocean deep water ventilation was enhanced, which favored the preservation of CaCO3 and increased the MAR-CaCO3; at 0.85~0.55 Ma BP, CO2-3 depleted Circumpolar Deep Water was enhanced, resulting in the dissolution of CaCO3, and the rise of lysocline and decrease of MAR-CaCO3.