Atmospheric pollutions have been found to modify particle hygroscopicity and aerosol ability to become cloud condensation nuclei (CCN). Aerosols and bulk CCN were measured in urban Guangzhou during pollution periods in January 2016, and particle liquid water content (PLWC) and aerosol acidity (Aero-pH) were calculated to examine their possible effects on aerosol CCN activation. The results showed that PLWC and Aero-pH are likely to play key roles in enhancing aerosol activation in the early stages of pollution episodes. With analysis of calculated and observed data, CCN, PLWC, Aero-pH and water soluble inorganic matter (WSIM) are demonstrated to link closely with each other, particularly in nocturnal times, and Aero-pH and PLWC are found to act as pre-occurring indicators of activated aerosols and aerosol activity during pollution eruption, respectively. The feedback of chemical reactions, aerosol acidity and particle water content is in theory conducive to explain changes of aerosol activation accompanying with particle accumulating and aging. Our analysis provides some insights into the formation of explosive particle pollution characterized by secondary aerosols, and suggests a possible approach to track or characterize the effects of rapid pollution formation on aerosol activation changes into CCN without measurements of CCN and aerosol number.