Fluorenylidene chalcone derivatives were synthesized by condensation. The structure of these compounds were ascertained by means of UV, melting point, IR and $^1H-NMR$ spectra. The nucleophilic addition reaction kinetics of Thioglycolic acid to fluorenylidene chalcone was investigate by UV in 20% $dioxane-H_2O$ at $25^{circ}C$. The rate equation which were applied over a wide $pH1.0{sim}13.0$ range. On the basis of general base catalysis and confirmation of addition reaction product, the nucleophilic addtion reaction kinetics of thioglycolic acid to fluorenylidene chalcone were measured by the pH change. From the result of the above caption, a plausible nucleophilic addition reaction mechanism of thioglycolic acid to fluorenylidene chalcone was proposed. These compounds may be used as the starting materials for the preparation of the engineering plastics or the germicide.