Seasonal and diurnal variations of the cloud are profoundly affected by the large-scale environment and the local topography. In this study, the one-year-long simulation was conducted by a two-dimensional Cloud Resolving Model over the eastern Tibetan Plateau (ETP) and two sub-region of East China (EC), which are the middle and low reaches of the Yangtze River and Pearl River Delta. It found that deep convections (DCCs) can hardly happen in the cold season over the ETP while it can happen all the year around over the EC, and it is about 20-30% thinner in the ETP than in the EC. Most of EC rainfall events (Precipitation Intensity, PI> 2.5 mm hr) relates to DCCs with cloud ice processes during the warm season. Because of the high elevation, the ETP warm-season freezing level is much lower than that of EC, making a favorable condition for cloud ice processes. DCCs are responsible for the diurnal variations of warm-season rainfall in all the regions. Warn-season DCCs have the greatest total cloud water content and frequency in the afternoon over the ETP, resulting in the afternoon peak of rainfall events. Besides the afternoon peak, rainfall events also have a nocturnal peak due to the DCCs over the ETP in spring, summer, and autumn. Strong surface heat fluxes around noon can trigger or promote DCCs in spring, summer, and autumn over the ETP, but only produce cumulus in winter due to the cold and dry environment.