Methylsilsesquioxane (Me-SSQ) was incorporated into cyanate ester resin (CE) to obtain organic-inorganic hybrids with better dielectric properties in this study. First, methyltriethoxysilane was hydrolyzed and condensed to synthesize Me-SSQ. Then several Me-SSQ/CE hybrids containing different contents of Me-SSQ were prepared. The effect of Me-SSQ content on the dielectric and hot/wet properties of materials was investigated. Results showed that the Me-SSQ/CE hybrid containing 20wt% of Me-SSQ shows a dielectric constant of 2.78, which is much lower than the pure CE resin. At the same time, the dielectric loss of the Me-SSQ/CE hybrids was slightly increased (tanδ<0.006). It indicates that Me-SSQ/CE hybrid is a promising matrix materials for high-performance printed circuit board (PCB).