The effect of stress on the physical properties of SBT thin films has been investigated. Both Remnant polarization (Pr) and spontaneous polarization (Ps) increase with the application of tensile stress, while decrease with the application of compressive stress. And the variation of Pr increase with the maximum testing voltage in the range 3-12V. The fatigue testing shows that a large voltage cycling before testing and the applied stress are both helpful to preventing the polarization suppression, and the result is explained by the coarsening of domains. The stress about 100Mpa seems to have no observable destructive effect on the SBT thin films.