In recent years there has been increasing interest in the synthesis of nanocrystalline metal oxides. Nanostructured garnets are of special interest due to their improved properties such as lower temperature sinterability, greater thermal stability, increased hardness, good optical properties etc. In our idea, the sol-gel method is a useful and attractive technique for the preparation of nanocrystalline powders because of its advantages: good stoichiometric control, the production of ultrafine particles and low temperature. In this paper, we reported the preparation and characterization of Yb3+ and Ho3+ codoped yttrium scandium gallium garnet (YSGG) nanocrystal powders by the sol-gel technique. The phase purity, mass loss, composition and microstructure features of the materials were analyzed by means of X-ray diffraction (XRD), TG analysis, infrared spectroscopy (IR) and transmission electron microscopy (TEM).