Microstructure of Cu-1.0Cr alloy in the non-steady directional solidification were observed in directional solidification at different growth rates to understand effects of the interface morphology in an initial transient zone on the steady solidified structure.The results reveal that the microstructure evolution of hypoeutectic Cu-1.0Cr alloy undergoes three stages:the planar primary α phase

the whole eutectic（α+β）to the dendrite α phase +eutectic（α+β）phase.With the increase of growth rates

the microstructure evolution in an initial transient zone is transferred from two stages

consisting of the planar primary α phase and the whole eutectic（α+β）

into one stage

being the single planar primary α phase

which shows that steady solidification structure can be controlled by interface morphology in an initial transient zone.The hypoeutectic Cu-Cr alloy with the whole eutectic structure can be obtained if structure evolution in non-steady unidirectional solidification process keeps in the form of planar interface for the binary Cu-Cr eutectic series alloy.