The evaluation of the reactivity of domestic limestones in the wet type flue gas desulfurization(FGD) process is important to maintain the performance and reliability of process, and to utilize effectively the limestone sources in Korea and provide the basic data for design of FGD process. The dissolution rates of limestones were measured using the lab scale experimental apparatus based on the pH-stat method, and diluted sulfuric acid was used as an acidic feed instead of conventional hydrochloric acid. After identifying the good reproducibility of measurements, the dissolution rates were measured 4 times for 27 limestone samples collected from 21 domestic mines, respectively. The dissolution rates of domestic limestones were more dependent on the physical characteristics including average particle size and specific surface area than the chemical compositions such as CaCO3 and MgCO3 contents of selected limestone samples under these experimental conditions. And the dissolution rates of limestones were affected by the physical processing of limestones including grinding methods.