The feasibility of YTiOx as a high-k gate dielectric for germanium-metal-oxide-semiconductor (MOS) devices has been investigated. The effects of different concentration of TiOx on electrical properties of YTiOx-based MOS capacitors are reported. It has been demonstrated that higher TiOx concentration in YTiOx may help to boost up dielectric constant while it causes serious damage to the interfacial properties. It has been observed that YTiOx film can effectively prevent re-growth of GeOx-based interfacial layer likely due to formation of stable Y-Ti-germanate at the interface in consequence of strong interaction of YTiOx with underlying Ge substrate. Indeed, YTiO x with 22% TiOx exhibits fairly good electrical characteristics with high dielectric constant value of κ∼21±1. The potentiality of YTiOx has further been examined with gate oxide downscaling and the results are compared with that of regularly used high-κ dielectrics promising for Ge MOSFETs.