The effects of aerosol on clouds are examined over the Yangtze River Delta (YRD) using 3-month satellite data during polluted wintertime from December 2013 to February 2014. The relationships between aerosol properties and cloud micro- and macro-physical parameters are analyzed in detail to clarify the differences in cloud development under various aerosol and meteorology conditions. Complex relationships between aerosol optical depth (AOD) and cloud droplet radius (CDR), liquid water path (LWP) and cloud optical thickness (COT) exist in four regions of interest (ROIs). High aerosol loading does not obviously affect LWPs and COTs. In fact, an inhibiting effect of aerosol on cloud development occurs over coastal areas for low-and medium-low clouds, more pronounced in low clouds (< 5 km) than high clouds. Low aerosol loading plays a positive role in promoting COTs of the high- and low-clouds over areas dominated by maritime aerosol. Aerosol loading exerts a significant effect on COTs, LWPs, CDRs in valley and coal industry districts except for high-cloud conditions. The value ranges of COTs, LWPs, CDRs in dry-polluted areas are lower than in other places, which suggests the dust aerosol has little effect on cloud properties. Synoptic conditions also cast strong impacts on cloud distribution, in particular an unstable synoptic condition leads to cloud development at larger horizontal and vertical scales. Ground pollution enhances the amount of low-level cloud even under stable conditions. Aerosol plays an important role in cloud evolution in the low layers of the troposphere (< 5 km) for the case of a stable atmosphere in wintertime.