Abstract:During the spring 2017, precipitation averaged over China is 139.1 mm, close to normal. The spatial distribution presents the “more in west and less in east” anomalous pattern. The spring temperature is close to or above normal over the most part of China, with average temperature is 11.1℃, 0.7℃ above normal. The Pacific decadal oscillation is at the positive phase, which provides a warm decadal background. Besides, the zonal pattern of atmospheric anomalies dominates the North Asia, the East Asia trough is more eastern than normal, and the positive geopotential height at 500 hPa controls most China, co leading to the warm condition in the preceding spring. In addition, the SST of the equatorial central and eastern Pacific is lower than normal, accompanied by warm SST anomalies at over the subtropical Pacific and West Pacific Region, which is good for less precipitation in South China and Northeast China, and more precipitation in Southwest China during the following spring. For the internal causes, Northeast China, South China, and Jiangnan Areas are dominated by the north wind and water vapor divergent anomalies, which may lead to the less precipitation in these regions. However, warm water vapor from the Bay of Bengal encounters with the north cold wind from the plateau, producing more precipitation over the Southwest China. This is another major cause for the circulation anomaly in 2017.