In the project investigations of Fe precipitation on rutile TiO­2(110),(100) and (001) have been undertaken. The preparation method of Fe-rich nanocrystals composed of Fe/Fe2O3/FeTiO3 has been determined. The chemical composition of of Fe-doped TiO2 single crystals has been explored using XPS/AES techniques, the structure has been determined using LEED/STM/AFM methods and electronic properties have been investigated with STS/CITS/UPS techniques. Apart from a fundamental importance of the performed investigations, they are also essential for the photocatalytic applications. The Fe/TiO2 system exhibits higher photocatalytic efficiency than pure Fe or Ti oxides. Till now no systematic studies of Fe precipitation and its oxides on TiO2 surfaces have been performed. Thus, the obtained results sched a new light on Fe/TiO2 system. In the project for the first time scanning tunnelling microscopy combined with the spectroscopy mode (STS) have been utilized to resolve structural and electronic properties of single nanocrystals. The new findings can be also important for spintronic applications where diluted magnetic semiconductors are desired materials.