Abstract: Metal-organic framework with coordinatedly unsaturated metal site, MIL-101, was functionalized with amino group through a post-synthetic method. The material was characterized by XRD, N2 adsorption-desorption measurement, elemental analysis, and then tested as a catalyst for the Knoevenagel reaction. The characterization result shows that amino groups were successfully incorporated into the framework of MIL-101 without destroying the pore structure. Amino-functionalized MIL-101 was proved to be highly active for Knoevenagel reaction. When the catalyst amount is 0.05 g, reaction time is 1h, the conversion of benzaldehyde reached 97%. Furthermore, this catalyst did not suffer from a leaching problem during the course of catalysis.