The ultrafast nonlinear optical response of Ag:BaTiO3 composite films synthesized by pulse laser deposition (PLD) is studied at the near-ultraviolet (400 nm) wavelength. The pulse duration of the laser used in the measurement is 200 fs. The real and imaginary parts of the third-order nonlinear susceptibility 'chi'(3) of the composite materials are measured. The composite films indicate self-focusing effect and nonlinear saturation, the values of Re'chi'(3) and Im'chi'(3) are measured to be 3.42*10^(-10) and -1.37*10^(-10) esu respectively, which are much lower than those reported before. It is mainly because that the duration of the laser used in the measurements is too short to induce the hot electron excitation and the thermal effect. The ultrafast nonlinear saturated absorption response of the Ag:BaTiO3 composite films may have potential applications for femtosecond laser mode locking.