Abstarct: In recent years, there has been increasing interest in ZnO semiconductors for optoelectronic application in the UV wavelength region due to its large exciton binding energy of 60 meV and wide bandgap energy of 3.37 eV at room temperature. One-dimensional ZnO nanostructures such as nanorods or nanowires have been considered as promising candidates for UV sensing and detecting applications owing to its high surface to volume ratio. In this thesis work, synthesis and growth of ZnO nanowires by chemical bath deposition and effective factors on their quality were studied. Also, UV mextal-semiconductor-mextal (MSM) photodetector baxsed on ZnO nanowires was fabricated successfully by using interdigitated silver electrodes on the ZnO nanowires surface. The device performance was characterized by current-voltage (I-V) characteristics in the dark and under UV light, photoresponse, quantum efficiency and time response as UV-LED light switching on and off. Effect of seeding modification of a glass substrate on the growth of ZnO nanowires and their UV detection properties have been investigated. Seeding functionalization was carried out by two methods including several times dip-coating inside a zinc acetate solution and coating of ZnO on the substrate by sputtering. The functionalized substrates then were used for growth of ZnO nanowires by chemical bath deposition. Various characterizations of the nanowires indicate that the seeding of both methods leads to formation of long nanowires with hexagonal cross section. The substrate was prepred y sputtering is dense.The enhancement in quantum efficiency from 4% to 50% and three order improvement in photocurrent measurement under UV illumination indicates the superiority of the sputtering pre-seeding in compration with dip-coating pre-seeding. In addition, the influence of post-annealing on the structural, optical and electrical of ZnO nanowires were investigated by varying temperature and atmosphere while time and heating rate were kept constant. High intensity of (002) peak in XRD, high crystallinity percent, high absorbancein ultraviolet region and sharp ultraviolet emission appears that the sample annealed at 400 °C has the better crystalline quality. According to this result, 400 °C was considered as the temperature annealing in pure oxygen and argon atmospheres. The time transient response of photodetector decreases to significant value of 4.6 s. Post-annealing in pure oxygen atmosphere increases the sensivity to UV light. So, the ZnO nanowires were grown on sputtering seed laxyer were annealed in pure oxygen atmosphere at different temperatures. The UV-Visible spectroscopy and photoluminescence results show that increase temperature annealing have a significant effect on performance of samples. Further, dual doping (Ag,N) ZnO nanowires expands the photoresponse and quantum efficiency of MSM photodetectors.