The results from microstructure and phase composition investigations of titanium in different structural states (with average grain sizes of 0.3 μm, 1.5 μm, and 17 μm) are presented following Al ion implantation using the Mevva-V.RU source (irradiating dose, 1018 ion/cm2). The implanted multiphase layers are found to form on the base of α-Ti grains. The size, shape, and localization of the formed phases (TiO2, Ti2O, TiC, Ti3Al, Al3Ti) depend strongly on the grain size of titanium target. It is shown that the nanostructural particles of TiO2 phase are located mainly on dislocations in the body of target grains. A Ti2O surface layer is found to arise in titanium with a grain size of 17 μm. It is established that an ordered Ti3Al phase is located at a depth of more than 200 nm in the implanted layer along the bounaries of the titanium grains.