Abstract: Based on the month precipitation data from 1964 to 2013 of 573 meteorological stations provided by China Meteorological Data Sharing Service System, the interdecadal fluctuation of the typical rainfall contours (200 mm, 400 mm and 800 mm) in China are analyzed from the points of the spatial shift and trends. The following conclusions are drawn: (1)On the whole, the 200 mm, 400 mm and 800 mm rainfall contours had spatial shift trend to northeast-southwest in the recent 54 years. (2)In recent 54 years, the 200 mm rainfall contour fluctuated greatly in the Ningxia Plain and the midwest of Tibet with the spatial shift trend to eastern and southern. The 200 mm rainfall contour shifted eastward in 1970s, 1980s, 2000s, whereas it moved westward in 1990s, the early 2010s in the Ningxia Plain. The 200 mm rainfall contour shifted westward and northward in central Tibet since 1980s and the area with rainfall more than 200 mm increased in the north of Xinjiang. (3)The 400 mm rainfall contour shifted eastward in 1970s, 2000s and westward in 1980s,1990s and the early 2010s, and the whole trend was to the east and south in middle of North China despite the great interdecadal variation. (4)The 800 mm rainfall contour shifted northward in 1980s, 2000s and shifted southward in 1970s, 1990s and the early 2010s in the Qinling-Huaihe area. The 800 mm rainfall contour had southern migration integrally.

Key words: rainfall contours, interdecadal fluctuation, climate change