The effect of the growth velocity on the microstructure evolution of Cu-1.54 wt% Cr alloy under directional solidification was investigated. The cellular eutectic structure was observed at 50 mu m/s. However, a centered Cr-rich beta dendritic structure surrounded by a layer of Cu-rich alpha phase and a eutectic structure between Cu-rich alpha phase and Cr-rich beta phase were observed when a sample solidified at a rate faster than 50 mu m/s. A microstructure of a centered Cr-rich beta equiaxed dendritic structure covered by a Cu-rich alpha phase grew at temperatures higher than the eutectic interface temperature. This paper explains the mechanism of the microstructure formation as a function of growth velocity. (C) 2012 Elsevier B.V. All rights reserved.