ZnS films are produced on the glass and quartz substrates by sulfidation of the as-sputtered ZnO films in the H２S-H２-N2 mixtu re. The properties of the f ilms are characterized by using the XRD, SEM and transmission measurements. The results show that the ZnS films with a hexagonol structure have a (002) preferre d orientation. The crystallinity and optical transmission spectra of the ZnS fil ms are related to working pressure and Ar/O２ ratio during the deposi tion of t he ZnO films. At the pressure >1Pa, the thickness of the ZnS films is very sma ll, while at the pressure ２ ratio higher or lower than 4∶1 will leads to the poor crystalline ZnS films. Also it is found that the ZnS films formed from the unannealed ZnO films almost have the same grain size as those formed from th e in-air annealed ZnO films, due to the high (002) preferred orientation during the growth of the ZnS films.