This study deals with the degradation of poly(ethylene-co-vinylacetate) (EVA)/polylactide (PLA) blend and EVA/PLA/TiO nanocomposites under accelerated weathering stimulation. The aging process was carried out by alternating cycles of UV light and moisture at controlled and elevated temperatures. The degradation of these materials was characterized by Fourier transform infrared spectroscopy (FTIR), color difference measurement, tensile test, thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM) observation. The FTIR and color difference results showed that the chemical structure of the blend and nanocomposites underwent changes during the weathering process. After the testing, the tensile properties and thermal stability of both the blend and nanocomposites showed a considerable reduction. The appearance of many micro-holes and micro-pores on the surface of the collected samples was observed. The presence of TiO nanoparticles promoted the degradation of EVA/PLA blend.