Strain technology is commonly considered as an effective means for enhancing MOSFET performance.The mechanical stress induced by wafer bending method is widely used for understanding the physical mechanisms of electron devices with strain.Though some papers have already discussed the DC performance of bulk and silicon-on-insulator(SOI)MOSFETs under mechanical stress [1-3],the impact of back gate bias has not been considered yet.In this paper,the effect of tensile uniaxial strain on the performance of SOI n-MOSFET as a function of gate length and back gate bias are studied.The uniaxial tensile strain along the current flow direction enhances the drain current of the n-MOSFET.It is found that for the on-state current,the magnitude of the fractional change is independent of back gate bias.While for the off-state current,the fiactional change is decreased under lower positive back gate bias,which should be attributed to the effective electron mobility lowering.And also the magnitude of the fractional change in drain current decreases as gate length is reduced from 10 to 0.13 μm,which is consistent with earlier reports.