||Zeolitic Imidazolate Framework-8 (ZIF-8)-based membrane are promising for hydrogen separation due to its molecular sieving property with the pore size of 4.0 Å. To enhance the gas separation performance, the study of tuning pore size has been developed. Recently, the pore size of ZIF-8 has been tailored by post-treatment such as thermal or vapor ligand treatment. However, post-treatment modification is required to well synthesized ZIF-8 membrane and extra steps. Herein, we introduced graphene oxide nanoribbons (GONR) on the polymeric support. Oxygen functional groups and sp2 carbon domain of GONR enhanced the direct growth of ZIF-8 crystal on the polymeric support and the rigidity of ZIF-8 by anchoring ZIF-8 layer due to metal-carbon chemisorption. Therefore, the tailored pore size of ZIF-8 was 3.6 Å, showing good gas separation for carbon dioxide/methane and CO2 permeance of 4 × 10-9 mol/m2·pa·s.