The present research carried out to stabilize nano-ZrO 2 on the wool fabric using citric acid (CA) as a crosslinking agent and sodium hypophosphite (SHP) as a catalyst under UV irradiation. The influence of the amount of nano-ZrO 2 on the performance of wool fiber was investigated by the use of Fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray spectroscope (EDX) and reflectance spectrophotometer (RS). The possible interactions between nano-ZrO 2 particles, cross-linking agent and wool free radicals were elucidated by the FTIR spectroscopy. Results indicated that the stabilized nano-ZrO 2 enhances the thermal stability of wool. Photo-catalytic activities of the coated wool were evaluated through degradation of methylene blue (MB) under UV irradiation.