The variability of seasonal-mean precipitation in southern China exists in three dominant modes: the first leading mode features consistent precipitation variation nearly over the whole part of southern China. The other two leading modes describe an out-of-phase relationship of precipitation anomalies between the middle and lower reaches of the Yangtze River Basin and the south of the basin and between the southeast and southwest China, respectively. The regional-averaged precipitation in southern China is characterized by obviously interdecadal and long-term changes in all the four seasons, of which the precipitation in summer has similar interdecadal changes with that in winter but contrasts with that in autumn during 1961-2013. Additionally, the interdecadal temporal turning points of precipitation anomalies are different in different seasons in the recent three decades. The spring and autumn precipitation anomalies enter into dry phase after the early 2000s and the mid-late 1980s, respectively, while the winter and summer precipitation anomalies go into wet phase after the middle 1980s and early 1990s, respectively. The summer and winter precipitation anomalies gradually become neutral since the early 2000s. Furthermore, the regional-averaged precipitation in southern China shows a decreasing trend in spring and autumn, but an increasing one in summer and winter during 1961-2013. In southwest China, precipitation decreases in all the four seasons except spring, and, in particular, the decreasing trend is the most remarkable in autumn. However, the linear trends of seasonal-averaged precipitation and drought/flood days are not so significant in most parts of southern China, because the interdecadal component has a relatively important contribution to the precipitation variability in southern China during this period. Finally, the results shows that interdecadal component has great (weak) contribution to the variability of total area affected by flood (drought) disaster in southern China, and in southwest China, the variability of total area affected by flood/drought disaster is mainly dominated by the interannual changes in the recent decade.