Thin films of CdS were prepared from an solution containing Cd(Ac)₂, NH₄OH, NH₄Ac and (NH₂)₂CS for solar cells. Growth rate of CdS films was increased with increasing temperature of reactive solution and with decreasing concentration of NH₄OH. Optical transmittances were more than 60%, independent with temperature and concentrations and was changed with thickness of CdS films. Grown films mostly showed the presence of polycrystallines with mixed cubic and hexaginal phases, but showed the hexagonal preferred phases in some growth condition. The resistivities of CdS were decreased by doping boron and criticial amount of dopant was determined.