The effects of aerosol on clouds are examined over the Yangtze River Delta (YRD) using 3 months of satellite data from the 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 meteorological conditions. Complex relationships between the aerosol optical depth (AOD), and the 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, aerosols inhibit development of low- and medium-low clouds over coastal areas—an effect that is more pronounced in low clouds (< 5 km) than high ones. Low aerosol loading plays a positive role in promoting the COT of high- and low-clouds over areas dominated by maritime aerosol. Aerosol loading exerts a significant influence on COTs, LWPs and CDRs in valley and coal industry districts except during high-cloud conditions. The ranges of COTs, LWPs and CDRs in dry-polluted areas are lower than in other places, which suggests that dust aerosol has little effect on cloud properties. Synoptic conditions also strongly impact cloud distribution, in particular, an unstable synoptic condition leads to cloud development on a larger horizontal and vertical scale. Ground pollution enhances the amount of low-level cloud cover even under stable conditions. Aerosol plays an important role in wintertime cloud evolution in the low layers of the troposphere (< 5 km) when the atmosphere is stable.