Graded InxGa1-xP buffer layers were grown on GaP substrate in order to prepare optically transparent substrate for optoelectronic structures. In our contribution we present results from the optimization of the growth process. We found different optimal growth conditions for GaP buffer layer growth and subsequent deposition of ln(x)Ga(1-x)P layers with graded value of x(In). Structures with final composition x(In) = 0.33 and 0.27 were prepared using grading rates Of 10% x(In) /mum and 5% x(In) /mum. The buffer structures were step graded with the compositional step between two adjacent layers 1% x(In) and 3% x(In) and the step width of 100, 200 and 300nm. The subject of our investigation was the influence of structure design and growth conditions on buffer properties. Layer composition was determined using X-ray diffraction. Photoluminescence measurements served to find the composition at which the band gap changes from indirect to direct one. Surface morphology and surface roughness was characterized by atomic force microscopy and scanning electron microscopy. Transmission electron microscopy in cross-sectional view configuration was used for revealing the buffer microstructure. We found out that the V/III ratio has to be optimized during the buffer growth ill order to avoid the degradation in the top part of the buffer structure. (C) 2004 Elsevier B.V. All rights reserved.