The aim of this study is to improve the adhesion properties of Nylon 6.6 fiber utilized as tire reinforcing materials, to the natural rubber compounds by using polyhedral oligomeric silsesquioxane (POSS) nanoparticles. In this study, metacryl POSS (M-POSS), which is a new generation additive/reinforcing filler, has been incorporated to a model (reference) natural rubber (NR) based skim compound. M-POSS was assumed to directly accompany with vulcanization reaction thanks to its double bonds. It is also expected that it can chemically and/or physically interact with skim compounds via their reactive side groups. Adhesion characteristics of the compounds have been investigated by means of strip H-adhesion tests and thermodynamic work of adhesion measurements. Thermodynamic work of adhesion values were calculated for rubber matrix and reinforcing fiber couples. Distinguishing cured and uncured surface energy enabled to evaluate pure adhesion and possible reactions during vulcanization, separately. It was concluded that incorporating M-POSS to NR based skim compound improved the adhesion between rubber matrix and Nylon 6.6 fiber.