<p>The effects of chemical composition and size of sea salt-containing particles on their cloud condensation nuclei (CCN) activity are incompletely understood. We used a ground-based counterflow virtual impactor (GCVI) coupled with a single particle aerosol mass spectrometer (SPAMS) to characterize chemical composition of submicron (dry diameter of 0.2–1.0 μm) and supermicron (dry diameter of 1.0–2.0 μm) sea salt-containing cloud residues (dried cloud droplets) at Mount Nanling, southern China. Seven cut sizes (7.5–14 μm) of cloud droplets were set in the GCVI system. Approximately 20 % (by number) of the submicron cloud residues included sea salt-containing particles at the cut size of 7.5 μm, which was significantly higher than the percentages at the cut sizes of 8–14 μm (below 2 %). This difference was likely to be involved in the change in the chemical composition. For the cut size of 7.5 μm, nitrate was internally mixed with over 90 % of the submicron sea salt-containing cloud residues, which was higher than sulfate (20 %), ammonium (below 1 %), amines (6 %), hydrocarbon organic species (2 %), and organic acids (4 %). However, nitrate, sulfate, ammonium, amines, hydrocarbon organic species, and organic acids were internally mixed with over 90 %, over 80 %, 39–84 %, 71–86 %, 52–90 %, and 32–77 %, respectively, of the submicron sea salt-containing cloud residues for the cut sizes of 8–14 μm. The proportion of sea salt-containing particles in the supermicron cloud residues generally increased as a function of cut size, and their CCN activity was less influenced by chemical composition. This study highlights the different distribution of the submicron and supermicron sea salt-containing particles in various cloud droplets, which might further influence their atmospheric residence time.</p>