ERA-interim reanalysis, Chinese precipitation, global sea surface temperature (SST) and precipitation datasets are used to study the spatiotemporal variation of heat sources over the western Pacific (WP) - Maritime Continent (MC) in winter and their impacts on regional climate. Results indicate that both WP and MC heat sources in winter exhibit significant interannual variations while the MC heat source also has a profound inter-decadal variation. The East Asian winter subtropical jet stream (EASJS) is closely related to the WP heat source with its axis shifting northward by 3 -4° in strong heat source years in comparison with weak heat source years, together with a stronger East Asian winter monsoon (EAWM). The WC heat source also has a marked negative correlation with precipitation over most areas of east China both in winter and the following spring. Due to the high correlation between the WP heat source and ENSO, the WP heat source still has a marked impact on precipitation north of China, EASJS, and EAWM both in winter and the following spring when the ENSO signal is removed. The MC heat source experiences an abrupt change around 1993 with much warmer SST and lower sea level pressure (SLP) after the year. Further analysis shows that the MC source is closely related to the Walker circulation both on inter-annual and inter-decadal time scales, and the fact that the warming trend over MC islands is much higher than their surrounding oceans after 1993 leads to a larger sea-land thermal difference, which may trigger the long-term change in local heat source and Walker circulation, thus, playing a major role in affecting the SST distribution over the eastern Pacific and even the global warming stagnation.