Abstract:Based on the daily mean total cloud amount and precipitation data from 549 meteorological stations in China and NCEP/DOE-2 monthly mean and daily reanalysis data for the period 1980-2015, this paper analyzes the distribution, spatio-temporal variation characteristics of total clouds in China as well as their correlations to north boundary belt of East Asian subtropical summer monsoon, the advance and retreat process over time, and interdecadal change characteristics of their locations. The study sugg-ests that, spring cloud cover in Northwest China is more than that in Northeast while the cloud in summer shows the opposite distribution. Monthly variation of the cloud cover in China is mainly characterized by the increase and decrease in the range and zonal movement of great values. The amount of total cloud cover in monsoon region is stable during the early advancing period of summer monsoon while 〖JP2〗a large interannual〖JP〗 variation of cloud cover appears in the later stage. The variation of cloud cover can be divided into three distribution patterns: same anomaly in whole area, opposite anomalies in the south and north and opposite anomalies in the middle and northern (southern) regions. Besides, the pentad meridional movement of great cloud cover area and the advance and retreat process of subtropical summer monsoon have a consist-ency in time and space. The locations of 50% and 65% monthly mean total cloud lines of July and August correspond respectively to the northern edge and southern edge of the north boundary belt, sharing a synchronous advancing and retreating paces and the interdecadal position variation characteristics. From 1980s to 1990s, the climate of the north boundary belt got drier, but has become wetter since early 21st century.