A change of optical properties and surface topography of Cd1-xZnxTe crystal surface was observed after irradiation by laser. It was shown, that photoluminescence spectrum change is associated with an increase of Cd atoms concentration and reduction of Zn atoms concentration at the irradiated surface of the semiconductor. These changes are due to the redistribution of atoms at the surface layer of the semiconductor by a large gradient of temperature arising during irradiation. The nanostructures are observed on the surface of CdZnTe crystal irradiated by second harmonic of Nd:YAG laser radiation (LR) at intensities at 4.0 – 12.0 MW/cm2. Thermogradient effect (TGE) has a main role of nanostructure formation. A graded band gap structures with open and close optical window in cones like Cd1-xZnxTe crystal were formed.