Single phase CuGaS2 thin film with a highest diffraction peak of (1 12) at a diffraction angle (20) of 28.8degrees was made at a substrate temperature of 70degreesC, an annealing temperature of 350degreesC and an annealing time of 60 min. Second highest (2 0 4) peak was shown at diffraction angle of (2theta) 49.1degrees. Lattice constant of a and c of that CuGaS2 thin film was 5.37 and 10.54Angstrom, respectively. The greatest grain size of the thin film was about I Pin. The (1 12) peak of single phase of CuGaS2 thin film at an annealing temperature of 350degreesC with excess S supply appeared at a little higher about 10% than that of no excess S supply. The resistivity, mobility and hole density at room temperature of p-type CuGaS2 thin film was 1.4 Omega cm, 15cm(2)/V s and 2.9 x 10(17) cm(-3), respectively. It was known that carrier concentration had considerable effect than mobility on a variety of resistivity of the fabricated CuGaS2 thin film, and the polycrystalline CuGaS2 thin films were made at these. conditions were all p-type. (C) 2002 Elsevier Science B.V. All rights reserved.