Using the International Satellite Cloud Climatology Project (ISCCP) monthly climate dataset, the climatological features of the total cloud amount over the South China Sea (SCS) are studied by applying the methods of EOF， wavelet， MannKendall mutation analysis, etc. The results show that: (1) The spatial characteristic field of the total cloud amount over SCS is the northtosouth type. The partition line is near 16°N. The distribution in the north part is along latitudes, most obviously affected by the diversity of thermodynamics, and the distribution in the south part is along the coastline, most obviously affected by the diversity between ocean and lands. (2) There is the remarkable seasonal feature in the distribution of total cloud amount. It is the northsouth type in winner and spring, but the westeast type in summer and autumn. The seasonal transition occurs at April and October. (3) The abnormal total cloud amounts correspond to the climate abnormal years. In the year of abnormally increased total cloud amount, there often occur drought disasters in South China, while in the abnormally reducing year, there occur flood disasters. (4) There exists strong periodic oscillation in total cloud amount with the period being five years and weak period oscillation with the period being two years. (5) The abrupt change of the total cloud amount happened in 2006, and afterwards the total cloud amount has been increasing.