Dissolution of BaCO3 and its effect on the dispersion behavior of aqueous BaCO3 suspensions at various pH values have been investigated. The amount of leached Ba2+ decreases with increasing pH value, which agrees with thermodynamically calculated results. The dissolution of BaCO3 also causes an increase in pH value of the suspension, but the change decreases with increasing initial pH value. The isoelectric point (IEP) of leached BaCO3 powder is at a pH of similar to10-10.5 and remains unchanged with increasing solids loading. The IEP of BaCO3 shows no significant change with added KCl or K2CO3, but shifts to a higher pH with increasing concentration of added BaCl2.