In this article, flower-like CdS structures have been prepared by a hydrothermal method with SDBS as surfactant. The influences of different experimental conditions on the morphologies, UV-Vis and fluorescence properties of CdS have been investigated. The performances of CdS have been analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-Vis) and room-temperature photoluminescence (PL). The XRD result indicates that the flower-like CdS structures are of hexagonal phase. The FESEM results indicate that the main role of SDBS is to make the CdS crystals assemble together to form the flower-like structures. The UV-Vis results show CdS has a strong absorption in the ultraviolet region and visible-light region. The PL results show CdS has two emission peaks, respectively at 461 nm and 553 nm. The growth mechanism for the formation of flower-like CdS structures is also described.