Single phase CuInS2 thin film with a highest diffraction peak (112) at a diffraction angle (2Θ) of 27.7° was well made by SEL method at annealing temperature of 250℃ and annealing hour of 60 min in vacuum of 10(-3)Torr or in S ambience for an hour. And the peak of diffraction intensity at miller index (112) of CuInS2 thin film annealed in S ambience was shown a little higher about 11 % than in only vacuum. Single phase CuInS2 thin films were appeared from 0.85 to 1.26 of Cu/In composition ratio and sulfur composition ratios of CuInS2 thin films fabricated in S ambience were all over 50 atom%. Also when CuInS2 composition ratio was 1.03, CuInS2 thin film with chalcopyrite structure had the highest XRD peak (112). The largest lattice constant of a and grain size of CuInS2 thin film in S ambience was 5.63 Å and 1.2 ㎛ respectively. And the films in S ambience were all p-conduction type with resistivities of around 10(-1)Ω㎝.