Ceramics YAG can be produced with large volume and high doping concentration with very uniform doping ions distribution. In this work, vacuum reactive sintering method is used to fabricate the pure and rare eart doped YAG ceramics. The effects of stoichiometry, sintering aids, and sintering conditions on microstructure and further the optical quality of the sintered ceramics have been investigated. By the post-HIP treatment, the optical quality of the ceramic has been greatly improved. By using the develoed ceramics, varous applications such as laser gain media for solid state lasers, optical windows, protective windows for smart phones and etc. will be demonstrated.