Atmospheric $PM_{2.5}$ and $PM_{10}$ were measured to investigate their levels and water-soluble ions(${SO_4}^{2-},;{NO_3}^-,;{NO_2}^-,;Cl^-,;{NH_4}^+,;Na^+,;Ca^{2+},;Mg^{2+},;and;K^+$) in Daegu between February 17 and April 18, 2006. Four Asian dust episodes during the period were examined for the influence of Asian dust on the particulate properties. Daily $PM_{2.5};and;PM_{2.5-10}$ concentrations ranged between $10.83{sim}136.76{mu}g/m^3$ with a mean of $38.43{mu}g/m^3$ and $16.13{sim}409.13{mu}g/m^3$ with a mean of $79.98{mu}g/m^3$, respectively. For all measured ions the mean fractions of $PM_{2.5};and;PM_{2.5-10}$ were 51.8% and 28.9% being lowered to 30.7% and 9.4%, respectively, during the dust episodes. Secondary ions (i.e., non-sea salt ${SO_4}^{2-},;{NO_3}^-,;and;{NH_4}^+$) contributed 44.3% and 14.8% to $PM_{2.5};and;PM_{2.5-10}$, respectively, with a decreased contribution during the episodes. The average equivalent ratio of ${NH_4}^+$ to the sum of ${SO_4}^{2-};and;{NO_3}^-$ was 0.99 and 0.89 for $PM_{2.5};and;PM_{2.5-10}$, respectively, indicating high source strength of $NH_3$ and its dominance in the neutralization of the acidic ions. Correlations and charge balance between ions suggest that neutralization of the acidic ions results in substantial depletions of carbonate both in $PM_{2.5};and;PM_{2.5-10}$ and chloride only in $PM_{2.5}$.