Abstract: The reinforcement techniques have been widely adopted in modern aseismic design of high rock-fill dams.Nevertheless,how to evaluate the effects of reinforcement in aseismic design have become a very important problem.As compared with the minimum safety factors which were conventionally employed as the evaluation standard,the permanent deformation can better reflect the characteristics of rock-fill materials,ground motion input and the safety of reinforced dams.By use of the modified Newmark’s sliding wedge method,the effect of reinforcement in enhancing the stability of slopes in high rock-fill dams and restricting the permanent deformation of dams was investigated.Firstly,the limit intensity and limit strain of reinforcement were determined based on the stress-strain relationship of reinforcement-composite and rock-fill materials.Secondly,the location of potential sliding surfaces was determined via a combination of ant colony algorithm and Fellenius method.The yielding acceleration of potential sliding bodies considering of the limited stress of reinforcement layers and vertical acceleration was computed.Finally,the transient movements were accumulated under the overloadings.It was shown that the reinforcement could reduce the permanent deformation up to 80% and improve the aseismic stability of high rock-fill dams subjected to strong ground motion effectively.