Anomalous behaviors of spontaneous polarization in a binary mixture of
the chiral smectic and nun-chiral smectic liquid crystals have been f
ound. The spontaneous polarization P-s of the ferroelectric liquid cry
stal possessing high P-s decreases drastically upon doping with non-ch
iral smectic C liquid crystal. The sign inversion of P-s is observed i
n a mixture highly doped with non-chiral liquid crystal.