To modify the photoluminescence properties the Eu(DBM)3bath complexes were encapsulated into the sub-nanometer pores of aluminosilicates zeolites L and Y and characterized by X-ray diffraction (XRD), transmission electron micrographs (TEM), Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible (UV-vis) absorption spectra. The luminescent properties of the encapsulated composites (Eu-L and Eu-Y) were systematically studied. The results indicate that in both the two composites the crystal-field symmetry becomes lower, as a consequence, the 5D0-7F2 electronic-dipole transition relative to the 5D0-7F1 magnetic-dipole transition of Eu3+ increases in contrast to the pure complexes. The outer quantum efficiency of the Eu3+ emission and the photostability of Eu3+ are both improved considerably. The adsorption of water in the composites has influence on the thermostability and decay dynamics of the Eu3+ emission. In the composite Eu-L, which contains less water the thermostability of luminescence is improved considerably and the lifetime becomes longer in comparison to the pure complexes. Overall, zeolite L is a more ideal host material for modification of lanthanide complexes.