During the production from gas condensate reservoirs, as the bottom hole pressure drops below the dew point pressure, liquid drops out and forms condensate banking results in significant loss of gas condensate productivity. A new method for stimulating gas condensate wells is changing the rock wettability in the near well-bore regions through chemical treatments and increasing gas relative permeability subsequently. In this study, a new chemical treatment was developed to alter the wettability of water wet carbonate rocks to intermediate gas wet.This treatment was consisted of using a mixture of an anionic fluoro-surfactant with an optimized concentration and solvent mixture. All the experiments were handled on carbonate rocks that were prepared from Sarkhun field is located on south of Iran. Contact angle and spontaneous imbibition experiments were run to measure the wettability of carbonate samples. Scanning electron microscopy ( SEM ) and energy dispersive X-ray spectroscopy (EDAX) were also performed to monitor the amount of surfactant solutions which adsorbed on the rock surface. In order to evaluate the effect of the chemical treatment on wettability alteration, the gas relative permeability of the treated and untreated cores were determined by coreflood experiments and compared with each other. To make the coreflood experiments very similar to gas-condensate reservoir conditions, a synthetic gas-condensate mixture was prepared, the experiments were handled under the reservoir temperatures and pressures and initial brine saturation was made in the cores. The increase in gas relative permeability was quantified by comparing the gas relative permeabilities before and after the treatment. The contact angle and imbibition experiments optimized two appropriate surfactant solutions that were made by 1% surfactant Z in ethanol and 1% surfactant N.Z in water. From these experiment results, it seems that Z could be effective in the wettability alteration for both carbonate surface and core. However, N.Z which was successful in wettability alteration of surfaces did not have efficient affect in core scale by imbibition tests. The water and oil contact angles of the treated surfaces with the succeed solution were increasedfrom zero to 121° and 70°, water and oil imbibition were reduced significantly by 86.6% and 82.1% after the treatment too. The fluorine content percentages on the surface treated with Z were higher than N.Z, it could be concluded that the adsorption of the Z is more than N.Z. It seems that penetration of the Z is almost constant with different porosity of the surface; therefore the fluorine adsorption and concentration on these surfaces were approximately constant. Coreflood tests showed the enhancement of gas relative permeability by factors of 1.49 to 1.7 which demonstrated the chemical ability in wettability alteration of cores at reservoir conditions. The durability of the treatment solution in the reservoir with initial brine saturation was also examined by various brine saturations experiments. It can be seen from the results that the surfactant and its solution have stability with the synthetic brine and precipitate has not been occurred and blocked flow paths of the fluid. Finally, this surfactant has been effective on remedy the condensate banking and following could be able in improving the gas and condensate productivity of gas-condensate reservoirs. Keywords: Condensate blockage,fluorinated surfactant,wettability, contact angle, imbibition, EDAX, permeability