A series of hybrids based on lanthanide ions (Eu3+, Tb3+, Sm3+, Dy3+) activated yttrium metallic–organic framework of 1,3,5-benzenetricarboxylate [MOF-76(Y)] are synthesized by ion substitution under solvothermal conditions, which are isostructural with parent MOF-76(Y). Meanwhile, nanoscaled MOF-76(Y):Ln (Ln = Eu, Tb, Sm, Dy) can also be prepared with the assistance of a moderate reagent. The structure, composition and morphology of resulting materials are characterized by XRD, EDX and SEM. Photophysical properties of these hybrid systems are investigated in detail to reveal the characteristic emission of the corresponding Ln3+ ion under ultraviolet radiation. In a further study, the tunable emitting color of Eu3+ and Tb3+ co-activated MOF-76(Y) (x mol% Eu3+ : y mol% Tb3+ = 1 : 10, 5 : 10, 10 : 10, 10 : 5, 10 : 1) are discussed. The result indicates that the tunable optical properties of MOF-76(Y):Eu/Tb depend on the concentration of activated ions and excitation wavelength. In addition, polymer films, which are made of nanosized MOF-76(Y):Ln (Ln = Eu, Tb, Sm, Dy), are prepared in order to extend their potential application in optical devices.