In this present work, a zeolitic imidazolate framework, ZIF-8, an oil-soluble long chain Ionic Liquids, [OMIM][NTf2], was separately synthesized and characterized. Ex-situ preparation of [OMIM][NTf2]-ZIF8 (IL@ZIF8) nanostructures were performed solvothermal, and the products were specified by the several techniques including XRD, FESEM, H-NMR, FTIR, TGA and N2 adsorption-desorption. The products were evaluated as a highly effective material in visbreaking process of petroleum vacuum bottoms (PVBs). To best our knowledge, no was reported in survey on the literature for MOFs as conversion enhancer and viscosity modifier in a visbreaking process especially for atmospheric pressure and elevated temperatures of 375 -400 °C during maximum 120 min. Injection of a little amount of the synthesized products to PVBs caused to produce gaseous compounds, naphtha, middle distillates, lubricating oil and tar. However, viscosity measurement results revealed that IL@ZIF8 was ideally suited for viscosity reduction of PVBs up to 321% after cracking and conversion of PVBs to its distillates up to 1400%. Catalytic upgrading with IL@ZIF-8 also yielded a liquid with 50% light hydrocarbon without any further coke formation.