The enhancement mechanism for the second harmonic generation (SHG) of chromophores in chiral smectic liquid crystal environment has been studied. The liquid crystals (LCs) studied are SCE13 and its racemic version, SCE13R (British Drug House), the former of which has the chiral and the latter nonchiral smectic C phases at room temperature, respectively. The LCs are doped with 4-dimethylamino-4’-nitro. stilbenes (DANS) molecules in weight. It is found that the SHG intensity is enhanced by the doping of the DANS molecules.