Rough sets is widely applied to dealing with the information under uncertainty. The data mining technology based on the rough sets is being increasingly attached importance by mathematicians and computer scientists. This paper introduces the development process and basic characteristics of rough sets, the application of rough sets theory to the data mining, and the typical system of the data mining based on the rough sets, as well as the directions and fields for future researches. Finally, this paper discusses the necessities through combining rough sets theory and intelligent methods to process information.