Nanocomposite of poly (methacrylate) and spirobenzopyran-based fluorescent dye was synthesized via miniemulsion polymerization. In this study, hexadecane was used as a co-stabilizer. Considering the effect of dye concentration of nanocomposites, the kinetic behavior of synthesis of fluorescent nanocomposites and the rate of reactions (R (p)) were investigated. The resulting nanocomposite was characterized by FTIR, TGA, DLS, TEM, SEM, and fluorescent spectroscopic techniques. Different properties of nanocomposites are discussed in comparison to the neat latex and pure dye. The results show nano-hybrid structure that provides a protective microenvironment for improving the thermo-stability of fluorescent dyes.