The relationship between the CuPt-type ordering and the surface undulation in CdxZn1-xTe epitaxial layers grown on ZnTe buffer layers was investigated. The results of selected area electron diffraction pattern and transmission electron microscopy measurements showed that CuPt-type ordered structures were formed in the CdxZn1-xTe epitaxial layers. The atomic force microscopy image showed that the surface undulations were created from lattice mismatch between the CdxZn1-xTe ZnTe thin films and the GaAs substrate. The surface undulations provided the [110] steps, which enhanced the formation of CuPt-type ordering in highly strained CdxZn1-xTe epilayers. These results provide important information on the relationship between the microstructural and surface properties in lattice mismatched heteroepilayers in the CdxZn1-xTe/ZnTe system. (C) 2004 American Institute of Physics.