During the autumn of 2012, the surface air temperatures were below normal and the precipitation was above normal in most China, especially in the Northeast, North China, Jiangnan and South China. By analyzing the causes for the climatic anormaly, it is found that more precipitation in the Northeast and North China was closely related with the anomalous southeasterly moisture transport from the western North Pacific Ocean while precipitation anomalies in Jiangnan and South China were mainly influenced by the southwesterly warm and moist water vapor along the western boundary of the western North Pacific tropical high. Further analysis indicates that the sea surface temperature anomaly (SSTA) was the major extermal forcing factor for the climatic anomalies in the autumn of 2012. The significantly warm SSTA in the middle and high latitudes of the western North Pacific Ocean caused more precipitation in the Northeast and North China, whereas the positive tropical Indian Ocean dipole and weaker warm SSTA in the middle and eastern tropical Pacific Ocean were possibly conducive to more precipitation in Jiangnan and South China.