For the carbon dioxide capture and separation, lots of researches have been carried out. Most mature process for CO2 separation is an absorption technology consisting of an amine based absorbent and a pact column. Though this has high absorption efficiency, amine base absorbent is highly corrosive and degradable at operation temperature. Also it requires high energy consumption to regenerate absorbent and degassing CO2 from the absorbent. Pact column for CO2 absorption requires high building cost for its huge CO2 absorbing column. To overcome these problems, combination of membrane contactor and ionic liquid system for CO2 separation is having great attention. Because, these can make more compact and cost-effective system. Ionic liquid has an advantage of non-corrosive, non-volatile and low degradation sensitive nature compared with conventional amine based absorbent. And membrane contactor also has larger effect surface area than pack column system. To retain CO2 absorbing efficiency, membrane between liquid absorbent and CO2 gas should be intact without smearing from an absorbent to gas phase and without swelling of membrane by an absorbent. To prevent smearing and swelling, it needs to control membrane surface properties. Especially membrane should be hydrophobic to prevent wetting by hydrophobic ionic liquids. In this study, we used polypropylene (PP) membrane for a flat sheet membrane contactor(MSMC). Also PP membrane surfaces were modified using organosilanes or fluorosilanes and modified surfaces were confirmed using FT-IR and FE-SEM. Hydrophobicity of modified PP membrane was compared with water contact angle. Also contact angle between Ionic liquid and PP membrane was also investigated for the application to CO2 absorbing membrane contactor.