Abstract: So far, the ice cores from Antarctica have provided a high-resolution record of atmospheric CO₂concentration levels over the past 800000 years.A significant fact is that the atmospheric CO₂concentration variation with respect to change in temperature is almost synchronous throughout these eight glacial-interglacial cycles, ranging from about 180×10^-6 to 280×10^-6.While the terrestrial carbon pool is the source of atmospheric CO₂, the deep ocean acts as the sink of the atmospheric CO₂)which could explain the reduction of atmospheric CO₂concentration during the glacial period.However, lots of palynological and numerical simulated evidences reveal that tropical forest must have dominated the emerged Sunda Shelf in the South China Sea during the last glacial period (LGP), suggesting that the Sunda shelf may have played a role as an atmospheric carbon sink in the LGP.In order to better understand the carbon cycle and climate change, future research needs to subdivide the terrestrial carbon pool effectively with quantitative calculation.