Interaction between surfactant palm primary alkyl sulfonate (palm PAS) and tinania (TiO2) in nanofluid system have been studied. In this experiment, nanofluid is prepared as follow: a certain amount of titania is dispersing in a water as a host fluid, and then dissolving a certain amount of palm PAS into water and stirred followed with sonication. Characterisation of nanofluid is conducted by FTIR for chemical structure and UV Vis spectrofotometer for absorbance. The result shows a synergize interaction between surfactant and nanofluid. The presence of titania in surfactant solution will reduce the surfactantsurface tension from 32,7 mN/m to 31,5 mN/m and the presence of surfactant in nanofluid, will stabilize nanofluid system. The optimum ratio of titania: surfactant is 1: 10 (w/w).