Gadolinium gallium garnet (GGG) polycrystalline powders doped with Nd,Yb were prepared by coprecipitation method. The structure, phase and properties of powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and fluorescence spectroscopy. XRD analysis indicated that the crystallization of Nd,Yb:GGG powders occur at 900 ℃. SEM analysis showed that the morphology of the powders was irregular and the average radius is 68.74 nm. FTIR analysis manifested that pure Nd,Yb:GGG powders were formed at 900 ℃. The fluorescence spectrum revealed that the most strong emission of Nd,Yb:GGG powders was 1030 nm, which was attributed to ²F_5/2→²F_7/2 of Yb³⁺. The possible formation mechanism of Nd,Yb:GGG powders were preliminarily discussed.