The nanoimprinted behaviors of Cu-Ni alloys were studied through molecular dynamics simulation. The results from the simulations showed that the punching force and the internal energy of the specimen increased rapidly with increasing punch position and both of they at the elevated temperature were lower than that at the low temperature. The punching force of the specimen with a lower Ni content was higher than that with a higher Ni content, while the internal energy of specimen was reverse. In addition, the spring-back phenomenon was more obvious with increasing Ni components of Cu-Ni alloy after the punch was retrieved during the nanoimprinting process and that induced a smaller residual stress within the specimens. (C) 2007 Elsevier B.V. All rights reserved.