In recent decades the developing of technology and the economic growth of photocatalyst significantly have been increased. This caused the developing of their applications. because of availability, non-toxic nature, and biological and chemical stability the semiconductor nano structures are promising materials. Among these materials the nano zinc oxide (ZnO) possessing semiconductor type-n nature with a wide bandwidth (E g =3.37 eV) are officialy known as an excellent material for photocatalytic processes due to its high sensitivity to light, proper bandwidth, low cost, and environmental friendly properties. In this work, the aims are producing composite nonafibers of zinc oxide/ silver/ carbon nanotubes (ZnO/ Ag/ CNT) and investigating photocatalytic properties of these nanofibers under radiation of UV and visible light. At first, the ZnO nanofibers were produced by calcination of nanofilbers resulted of electrospinning polyvinyl alcohol and zinc acetate solution in water and ethanol solvents. Then, silver nitrate and carbon nanotubes were added in order to improving the photocatalytic property of the nanofiber. The potocatalytic property was evaluated. After evaluating the effect of the amounts of zinc acetate, silver nitrate, and carbon nanotubes on the resulting fibers photocatalytic property, the best results were achieved in ratios of 1:2 polyvinyl alcohol: zinc acetate, 1:3 polyvinyl alcohol: zinc acetate with the amount of 7.5% atomic silver nitrate, and 1:3 polyvinyl alcohol: zinc acetate with the amount of 7.5% atomic silver nitrate and 2.9% carbon nanotubes to the weight of carbon nanotubes, for ZnO nanofibers, ZnO/Ag nanofibers, and ZnO/Ag/CNT nanofibers; respectively. The X-Ray diffraction and elemental analysis confirmed the formation of zinc oxide and silver phases. The presence of carbon nanotubes resulted in reducing diameter and increasing specific surface of ZnO/Ag nanofibers. Also after the evaluating photoluminescence spectrum of nanofibers, it was observed that after adding silver and carbon nanotubes, the intensity of photoluminescence spectrum was decreased compared to pure zinc oxide. This result indicates the amount of electron-hole pairs recombination and improving of phtocatalytic property. According to obtained results, the phtocatalytic efficiency of ZnO nanofiberes was increased under UV from 39.4% to 67.7% and 74.5%, and under visible light from 38% to 57% and 71% by adding silver and carbon nonotubes; receptively. Key words: electrospinning, zinc oxide nanofiber, composite nanofiber, photocatalyst, silver, carbon nanotubes