Trends of the International Satellite Cloud Climatology Project (ISCCP) cloud water path (CWP) and total cloud amount (CA) are investigated for the period 1984-2004 over China. Annual trends in five climatic regions of China reveal that much of China experienced increases in CWP and decreases in CA except the Northeastern China where exhibited a slight increase in CA. The differences of trends in CWP and CA can also be found in spring, autumn and winter. In summer, most regions of China have undergone increasing trends in CWP and CA.

The decreasing trend of annual mean CA is similar to the results in previous studies using surface observations and conduces to more solar radiation to the earth surface. However, the increase in CWP which is closely related with cloud optical thickness makes an inverse influence on the radiation transmission and should be taken into more consideration when performing a surface solar radiation analysis. The seasonal trends in CWP and CA are mainly related to the changes in circulation, topography and relative humidity with analyses using NCEP Reanalysis dataset. The increasing trends in CWP and CA in summer are considered to be caused by the weakening summer monsoon since middle of 1980s.