Here we describe a one-step synthetic approach to construct NH2-MIL-125 (Ti) MOF encapsulated with highly dispersed palladium particles (Pd@MOF). In a facile synthesis, take Pd(PPh3)4 as Pd sources, P-ligand could be oxidized to remove. And Pd-MOF was constructed by a one-pot solventthermal method through in situ formative MOF to encapsulate Pd particles. Immersed-Pd/MOF was synthesized by a simple impregnation method. Unlike yellow colored NH2-MIL-125 (Ti) MOF, Pd@MOF, and Pd-MOF exhibit green but immersed-Pd/MOF exhibit gray color.