Abstract: Besides the winter mean temperature, the conspicuous intraseasonal oscillation of East Asia winter air temperature (EAT) also exerts a large influence on human activities and the economy. Based on the station data and the reanalysis data during the period of 1959–2018, the intraseasonal spatiotemporal variability of East Asian winter temperature was analyzed by using the method of season-reliant Empirical Orthogonal Function (S-EOF). The results show that the spatiotemporal variability of EAT is mainly characterized by the intraseasonal phase inversion variation pattern, which means warmer (colder) than normal in early winter and colder (warmer) in late winter. This mode accounts for 31.1% of the temperature variance. It is not a local phenomenon, but instead represents the intraseasonal winter temperature over the entire Asian continent. The circulation evolution of this mode is mainly characterized by the phase inversion of the Eurasian teleconnection pattern (EU) from a positive (negative) phase in early winter (December) to a negative (positive) phase in late winter (February), accompanied by the turning of lower Siberian high and Aleutian low intensity, and the intraseasonal evolution of the subtropical jet. The possible influencing factors which affect the EU phase reversal are as following: First, the circulation over the North Atlantic reverses between early winter and later winter and influences the EU through the North Atlantic heat flux. Second, wide and narrow sea surface temperature (SST) anomalies resulted from ENSO events also contribute to the reversal. In El Niño years, the events of wider (narrower) SST anomalies are more likely to inverse from the phase of warmer (colder) temperature in early winter to colder (warmer) temperature in late winter. When La Niña events occur, the influence is opposite.