Abstarct: Environmental Barrier Coatings (EBCs) are used as protective coatings for silicon carbide components in gas turbine engines to inhibit surface reactions with water vapor released by hydrocarbon combustion. In high temperature environment, oxidizing species such as H2O and O2 react with SiC to form gaseous CO and a solid SiO2 laxyer on the SiC surface. Subsequent reaction of the normally protective silica laxyer with water vapor leads to the formation of gaseous Si(OH)4, and volatilization of the silica scale at a rate that increases with temperature and water vapor pressure. On the other hand, thermochemical reactions between calcium-magnesium-aluminosilicate (CMAS) baxsed on sand and volcanic ash at temperatures above 1300°C lead to the degradation of ceramic components. In this study, the ytterbium monosilicate (Yb2SiO5) and mollite (3Al2O3.2SiO2) powders were synthesized and mixed with a specific content to be considered as an environmental barrier coating. Also, SiC/Cf composite substrate was produced by spark plasma sintering technique. The composite powder was granulated by spray dryer process and deposited on the SiC/Cf substrate by atmospheric plasma spray technique. Hot corrosion performance of the composite coatings was investigated in the CMAS (33Ca-9Mg-13Al-45Si) powder at 1300oC for 40 h. Phase analyses of synthesized powders, coating surface and hot corroded specimens were characterized by X-ray diffraction (XRD) technique. The scanning electron microscope equipped with energy dispersive spectroscopy (SEM, EDS) were used to study the powder morphology, substrate surface, coating cross-section and reaction laxyer of hot corroded samples. Nanoindentation test was used to study the hardness and elastic modulus of the coating and composite substrate. After spray dry processing, the powders have spherical morphology and good-flowability with a mean particle size of 20-40 µm. The coating thickness was between 100-150 μm, which has a hardness of about 8GPa and elastic modulus of about 111GPa. The hot corrosion behavior of the composite coating after 40 hours of reaction with CMAS at 1300oC showed acceptable decrease in reaction laxyer growth that mean more protection in substrate at high temperature.