Abstract: The geological and engineering conditions at the Din gma Stretch of Anqing Dyke are presented.Through the analyses on dangerous phen omena,covering layers and natural seepage fields,a safety assessment on the dyke foundation is performed and the necessity of dyke reinforcement is demonstrated .Ground water level data obtained by piezometric tubes in three typical years ar e analyzed.The results show that relief wells at Zhengjiacun,Sigugou and Wangjia cun still play an improtant role,but that at Dingjiacun,Wangjiadun and Xieweigua i have been choked obviously.It is concluded that relief wells should not be ra shly denied as a dyke reinforcement measure owing to the decreased effectiveness of some of them at some places.The improvement of design,consummation of constr uction technology and rational management of relief wells should be investgated in depth to make most of them efficient and to extend their service life.