TiO2 is one of the most promising photocatalysts in solar energy harvesting and environmental pollution control due to its low cost, non-toxicity, and chemical and thermal stability. Pure anatase is active only in UV spectral part but modified with gold it becomes active also in visible light. In the present work formation of active TiO2 nanoparticles in microwave synthesis and their modification with gold were studied. TiO2 P25 nanopowder and 10M KOH solution were used as raw materials. Microwave-assisted synthesis method [1;2] permitted to obtain TiO2 nanofibres with a diameter of 5nm and a specific surface area in the range of 70 - 150m2 /g. In order to modified TiO2 nanofibers with gold HAuCl4 (5g/L) water solution was added to suspended TiO2 nanofiber solution at temperature 35oC and pH 7. The resulting suspention was kept at 40 oC temperature and formaldehyde (3%) solution as reducing agent was added. The pH was adjusted to 6,5 by NH4OH water solution (1:2). The obtained gold modified TiO2 nanofiber powder was filtred, dried and calcinated at 500 oC for 2h. In SEM micrograps (Fig.1) show that TiO2 fibers consist of large amount of induvidual TiO2 nanowires before and after modification with gold. Gold content was determined by XRF analysis and it was 4.80wt%. Photocatalytic activity was determined by degradation of the methylene blue solution under UV and visible light irradiation. The gold modified nanofibers showed almost two times higher photocatalytic activity with respect to pure TiO2 nanofibers.