In this work technological properties of ceramic slurries based on Yttria for fabrication “prime coat” in ceramic shell moulds were characterized. Yttria with two different granulation (200# and 325#) in ratio (50%-50%, 35%-65% and 65%-35% by weight) was used for preparation ceramic slurries. Solid phase was 77% by weight. Technological properties like viscosity, dynamic viscosity, pH, plate weight test and density were done. For characterization yttrium III oxide SEM images, chemical composition and Zeta potential were investigated. Yttria based ceramic slurries had very promising properties and there are very perspective for future fabrication.