Abstract: The large-sized highly stable composite films, comprising Cd_xZn_1-xSe_yS_1-y quantum dots (QDs) and polyvinylidene fluoride (PVDF), were synthesized by doctor-blade coating with PVDF as the packaging material.The impact of the chloroform to dimethylformamide (DMF) ratio on the microstructures, optical properties and water/thermal stability of the QDs/PVDF coatings was investigated with X-ray diffraction, photoluminescence (PL) and ultraviolet visible (UV-Vis) spectroscopy.The results showed that the QDs embedded in PVDF coatings possess the same high PL properties as the QDs do.Irradiated by UV light, the blade-coated Cd_xZn_1-xSe_yS_1-y QDs/PVDF films, 8 cm×15 cm in size, emitted bright red light.In addition, boiling in water for 240 min little affected the extremely high water/thermal stability of the PL properties of the QDs/PVDF films.