Nano-sized Yttrium iron garnet (YIG;$Y_3Fe_5O_{12}$) particles have been synthesized by using coprecipitation and a heat treatment process. The YIG particles were made using a nitrate or a chloride salt solution. The pH concentration of the solution was fixed at 12. Spherical shaped YIG particles were made with a size of about 20 nm. The magnetization value of the particles was smaller than the bulk value but their coercive field showed a high value.