The main purpose of this study was to investigate air quality trends of ambient aerosol with obtaining size-fractionated information. The suspended particulate matters were continuously collected on membrane filters and glass fiber filters by an 8-stage cascade impactor for 2 years (Sep. 2005 $sim$ Sep. 2007) in Kyung Hee University-Global Campus. 8 ionic species ($Na^+$, ${NH_4}^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, ${NO_3}^-$, and ${SO_4}^{2-}$) were analyzed by an IC after performing proper pretreatments of each sample filter. The average concentration levels of each ion were $9.24{mu}g/m^3$ of ${SO_4}^{2-}$, $7.35{mu}g/m^3$ of ${NO_3}^-$, $2.81{mu}g/m^3$ of ${NH_4}^+$, $2.11{mu}g/m^3$ of $Ca^{2+}$, $1.65{mu}g/m^3$ of $Cl^-$, $1.87{mu}g/m^3$ of $Na^+$, $0.80{mu}g/m^3$ of $Mg^{2+}$, and $0.54{mu}g/m^3$ of $K^+$, respectively. The distribution pattern of $Na^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, and ${NO_3}^-$ was bi-modal and two peaks appeared in the range of $0.4{sim}0.7{mu}m$ and $3.3{sim}4.7{mu}m$, respectively. On the other hand, ${SO_4}^{2-}$, ${NH_4}^+$, and $K^+$ showed patterns of uni-modal distribution, mostly abounded in the fine mode group.