The characteristics and causes of the East Asian winter monsoon (EAWM) on centennial time scale were analyzed in this paper, based on the climate simulation results over the past 2000 years using the Community Earth System Model (CESM) with the low resolution (T31_g37, which is equivalent to 3.75° * 3.75°). It has an important scientific significance to recognize the climate change on centennial time scale and distinguish the influence of the external forcing on the EAWM. There are six experiments to be compared in this research, including control experiment (Ctrl), all forcings experiment (ALL),total solar irradiation experiment (TSI), volcanic eruptions experiment (Vol),greenhouse gases experiment (GHGs) and land use/land cover change experiment (LUCC). These experiments are carried out from 1 A.D. to 2000A.D. based on a 2400 years' control experiment under the A.D. 1850's initial forcing, except the volcanic eruptions experiment, which only span from 500A.D. to 2000A.D. We compared the climatology fields from the all forcings experiment and reanalysis data, and the time series of area averaged annual mean surface temperature anomaly over China from the all forcings experiment, reconstructions and those derived from the other model simulation data, in order to do the model validation. The methods of the empirical orthogonal function (EOF) and the regression analysis are used in this study to find out the characteristics and causes of East Asian winter temperature. The results show: The EOF1 mode of East Asian winter temperature anomalous on centennial time scale is an in-phase pattern in the whole region. Its physical meaning is the regional mean winter surface temperature over East Asia (EA). The origin of this mode is the total solar irradiation. When the whole region becomes cold, the dynamic structures of EOF1 are characterized by an enhanced sea level pressure (SLP) to the north of Lake Baikal, an intensive cyclone in north of Pacific Ocean and a deepening 500hPa geopotential height in the EA trough. The EOF2 mode of East Asian winter temperature anomalous on centennial time scale is a cold-south and warm-north (or vise versa) pattern. Its physical meaning is the temperature difference between northern EA and southern EA and the EOF2 mode is caused by the greenhouse gases,land use and land cover change and volcanic eruptions, simultaneously. The first two EOF modes of winter sea surface temperature (SST) affect the first two EOF modes of East Asian winter temperature respectively. The main cause of the first EOF mode of winter sea surface temperature is the total solar irradiation while the main cause of the EOF2 of sea surface temperature is the volcanic eruptions.