Abstract: Based on sol-gel spin-coating technique, the Sn-S films were prepared by the rapid pyrolysis, and the effects of S content in the precursor solutions were studied on the phase, morphology and band gap of the prepared films. The results indicated that the phases of the films were seriously affected by the S content in the film. The mixed phases of SnS₂ and Sn₂S₃ were observed in the films with lower S content, and then the mixed phases of SnS₂ and SnS were in the films with higher S content. Further, the phase formation mechanism of the films was tried to be discussed. Moreover, the morphologies and band gaps of the films were seriously affected by the phases. In addition, the annealing treatment at 450 ℃affected the phases and band gaps of the films to a certain extent, but few affected the morphologies.