Ag/ZnO nano-composite structures were synthesized on n-type (100) Si substrate s by simple hydrothermal and photodeposition method.The effects of Ag doping con centration on metal-enhanced fluorescence ZnO nanoflowers for are studied.The s tructure,morphology and optical properties of Ag/ZnO nano-composite structures have been characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM) an d photoluminescence (PL) spectroscopy, respectively.The SEM results show that ZnO nanoflowers are about 1μm in le ngth and around 200nm in diameter.The XRD patterns indicate that intensities of diffrac tion peaks of Ag/ZnO nano-composite structures are enhanced compared with undoped ZnO.The weak diffraction peak at 38.28° can be assigned to Ag₂O when the doping co n centration of Ag is 0.153wt.%.The PL spectra demonstrate that the UV luminou s intensity of ZnO is significantly influenced by the concentration of Ag.Ag/Zn O nano-composite structure has the strongest ultraviolet emission intensity whe n the doping concentration of Ag is 0.051wt.%.Compared with undoped ZnO,t he UV luminous intensity of Ag/ZnO nano-composite structures is increased by 11t imes due to the local surface plasma resonance (LSPR) effect of Ag nanoparticle. It is expected that the Ag/ZnO nano-composite structure can be used as a bilog ical fluorescent probe to further improve the sensitivity and selectivity of flu orescence detection.