To better understand the in-cloud enrichment of secondary inorganic ions, the chemical composition of individual particles during cloud events and cloud-free periods, as well as cloud water and PM_2.5 samples, were measured from August to September 2023 at Mt. Damaojian (1128 m a.s.l.) in southeastern China. Our results demonstrated that cloud processes promoted the aqueous-phase formation of ammonium, nitrate, and sulfate, but the degree of sulfate enrichment was lower than that observed for ammonium and nitrate. Furthermore, the average hourly relative peak area (RPA) of secondary inorganic ions revealed their selective enrichment in cloud droplets. The RPA of ammonium, nitrate, and sulfate in cloud droplet residual (RES) particles were 5.11, 3.05, and 1.43 times greater than those in cloud interstitial (INT) particles during two consecutive long-lasting cloud events, respectively. Both ammonium and nitrate showed ubiquitous enrichment across all particle types, including K-rich, Black carbon (BC), Metal, and Sea salt (SS) particles, although with distinct degrees of enrichment. Ammonium exhibited the highest degree of enrichment in the SS particles, whereas nitrate showed the most pronounced enhancement in the BC particles. Notably, the RPA of nitrate in all four types of particles exhibited a significant positive correlation with the liquid water content (LWC), reinforcing the role of aqueous-phase processing. Unlike ubiquitous ammonium and nitrate, sulfate enrichment was restricted to K-rich and Metal particles. The different enrichments of ammonium, nitrate, and sulfate underscore particle-specific influences on their in-cloud formation. These findings extend our current understanding of atmospheric chemistry in clouds.