Mullite-ZrO2(Y2O3) spherical nanoparticles with diameter in the range of 40-65 nm, containing t-, m-ZrO2 phases and traces of mullite were prepared by using thermal plasma. Combustion synthesis from appropriate salts water solution was performed in the presence of glycine at 500 oC during 2 h and additional calcination at 950 oC. The obtained powder contained mullite and t-ZrO2 phases with crystallite size of 25 and 15 nm respectively. Molten salts synthesis at 850-900 oC for 2 h allowed obtain crystalline mullite and t-ZrO2 nanoparticles with crystallite size of 60 nm, 55 nm respectively. The parameters of prepared nanoparticles and sinterability using spark plasma sintering were compared. The powders produced by plasma chemical synthesis showed higher sinterability. They allowed prepare fine-grained (0.8-1.4 µm) dense materials respectively. Molten salts synthesis at 850-900 oC for 2 h allowed obtain crystalline mullite and t-ZrO2 nanoparticles with crystallite size of 60 nm, 55 nm respectively. The parameters of prepared nanoparticles and sinterability using spark plasma sintering were compared. The powders produced by plasma chemical synthesis showed higher sinterability. They allowed prepare fine-grained (0.8-1.4 µm) dense materials (99.1%) at 1400 oC during 3 min.