Abstract: In ferroelectric liquid crystal with high polarization the dependence of the phase matched SHG intensity on cell thickness and temperature was studied. Sharp curve of phase matched SHG intensity was obtained and effective nonlinear optical cefficient was measured. We also studied the dynamic response of SHG under stepwise electric field, which was found to be composed of high speed response of hundreds of micro microseconds and comparatively slow response of hundreds of microseconds. Lastly we discussed these two responses on the basis of ferroelectric liquid crystal molecular structure.