The hydrophilic monodisperse ZnS nanoparticles were synthesized in the mixed surfactant system (oleic acid OLA and sodium dodecyl sulfate SDS). X-ray powder diffraction (XRD), UV-Vis absorption spectra, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy were used to characterize ZnS nanoparticles. The sizes of ZnS nanoparticles were determined to be about 5 nm using XRD. The photoluminescence properties indicated that ZnS nanoparticles exhibited a strong luminescent at 450 nm. It was found that PL and absorption intensity of ZnS nanoparticles increased with the increase of OLA/SDS molar ratio, and showed a maximum when ratio was 1:2. If SDS concentration continued to increase, the PL intensity would decrease. In addition, the results of the contact angle demonstrated that the hydrophilicity of ZnS nanoparticles have been improved greatly. (C) 2014 Elsevier B.V. All rights reserved.