Abstarct: In this research two modified mextal-organic freamworks were used as catalyst support due to their special properties. Chromium terephthalate (MIL-101) with high surface area (up to 4100 m2/g) contains many unsaturated mextal sites. It was prepared by hydrothermal processing (MIL-101) and then it was functionalized with diethylenetriamine (DETA-MIL-101) or 2-aminomethylpyridine (AMP-MIL-101). After that, vanadyl acetylacetonate was stabilized on pending amine groups and FT-IR, CHN, ICP, TG and SEM techniques were usead for the characterization of both V-DETA-MIL-101 and V-AMP-MIL-101 catalysts. Then they were used in epoxidation of cis-cyclooctene and the yields of product were investigated by GC. The catalytic procedure was optimized for different parameters. It was found that the optimized condition with over 96% yield for epoxidation 0.5 mmol of cis-cyclooctene in the presence of V-DETA-MIL-101 was 15 mg of catalyst, 1 ml CCl4 as solvent, and 1.12 mmol t-butyl-hydro-peroxide as oxidant at 80℃ after 15 min. But V-AMP-MIL-101 catalyst, showed lower activity and it was needed 20 mg catalysts to achive 96% yield after 60 min. In addition, recycling experiments revealed that V-DETA-MIL-101 catalyst can be repeatedly applied for nearly complete epoxidation of alkenes for at least four successive cycles.