Exfoliated polypropylene (PP)/layered double hydroxide (LDH) nanocomposites have been successfully synthesized via melt-intercalation. Their structure, thermal properties, and photo-oxidative behavior have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMA), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectrum. TGA and DMA data show that the PP/LDH nanocomposites have enhanced thermal stability compared with virgin PP and corresponding PP/montmorillonites (MMT) nanocomposites, especially in high temperature range during the thermal decomposition of the samples. XPS and FTIR results give positive evidence that the photo-oxidation mechanism of PP in the PP/LDH materials is not modified compared with that of virgin PP. However, photo-oxidation rate of PP/LDH materials is much lower than that of PP and PP/MMT samples, indicating that the PP/LDH nanocomposites have better UV-stability.