Flue gas desulfurization, a well-established clean coal technology, is imperative to the coal-combusted power plants. The lime-gypsum method, commonly used in the developed countries, of high investment and cost, little usage of product gypsum, is impossible to be widely adopted in China. The authors have proposed a proprietary and novel ammonia desulfurization process (NADS), which is able to recover SO₂ from flue gases, producing ammonium sulfate, or phosphate, or nitrate, and simultaneously concentrated sulfuric acid, commericialized on a 25MW unit. Compared with the conventional FGD processes, NADS can result in an investment reduction of more than 70% , and an operating cost reduction of more than 70%. In this papaer, economic feasibility studies have been done based upon a 200MW and a 300MW unit, with the results that the investments are 60 and 80 million RMB，respectively, and the capital payback periods are eight and five years respecfively. It can be speculated that the NADS can find great applications in China.