Abstract: On the whole, the distribution of summer precipitation over China in 2013 is flood in the north and drought in the south. The precipitation anomaly is more than usual in North China, the Northeast and Northwest, while that in the Huaihe River, Yungui Plateau and the south of Yangtze River is less than usual. The summer precipitation anomaly in 2013 has its particular background and physical mechanism. In this paper, we have analyzed the reason of the summer precipitation anomaly in two main aspects: firstly, the East Asian atmospheric circulation systems anomaly, which is corresponding with the summer rainfall anomaly, is analyzed. Results show that in 2013 the East Asian summer monsoon (EASM) is stronger, the Western Pacific Subtropical High (WPSH) is also stronger with the anomalous westward and northward movements of the WPSH, all of which strengthen the water vapor transport northward movements. At the same time, Eurasia mid-high latitude area is controlled by the cold low pressure, blocking high resistance less activity, which is adverse for the cold air moving southward. Cold and warm air masses confront each other in north China for a long time, leading to more precipitation in this area. Secondly, the prophase anomalies, such as previous winter sea surface temperature (SST) anomaly and the snow anomaly, which has a major impact on the atmospheric circulation in East Asia, have been discussed. Results show that from the previous winter to the summer in 2013, the east-central equatorial Pacific Ocean SST is lower while the north Indian Ocean and the northwest Pacific SST is higher. The summer tropical Walker circulation and Hadley circulation of West Pacific ocean is abnormal. In the south of West Pacific ocean especially near the sea of the Philippines, the convection of the tropical convergence zone is stronger, resulting in the northward of the WPSH and the strengthening of the EASM. The previous winter Eurasian snow anomaly is more than usual, which benefits for the cold deep low pressure in the south of the Lake Baikal, the enhancement of the East Asian subtropical westerly jet, and the northward and westward movements of the subtropical high. Not only the EASM circulation systems are affected by both SST and snow cover, but also there exists interaction between different systems, which is the direct reason for the regional precipitation anomaly distribution.