Abstract: By absorption of the definition proposed by Rowe and Kahn and based on the concept of in-depth leisure sports suggested by Stebbins, a Canadian scholar, an in-depth interview is carried out among the senior swimmers on the winter swimming team of Deyang. And by application of grounded theory paradigm, an exploration is made into the effects of in-depth leisure sports upon elderly people's successful ageing, which brings us to the following conclusions: the in-depth leisure sports, by means of giving the elderly participants the sense of physical health, positive feelings and the sense of belonging, promote their successful ageing whether in terms of the physical, mental or social well-being.