FOUR CATIONIC Gemini surfactants were synthesized and characterized using different tools. Their surface activities were measured using surface and interfacial tension measurements. The effect of their spacer chain length on the surface activity, emulsification power and interfacial tension was studied. The thermodynamic parameters showed the tendency towards micellization and adsorption. The results showed that longer spacers increased the micellization tendencies of the surfactants, while shorter spacers increased the adsorption propensity at the air-water interface.