We have investigated the optoelectronic memories and switches based on the charge trapping/detrapping effect for the binary liquid crystal composed of N -(4-decyloxybenzylidene)-4'-(dimethylamino) aniline as a hole acceptor, and N -(4-decyloxybenzylidene)-4'-nitroaniline as an electron acceptor. The smectic phase of the binary liquid-crystal led to a large improvement of the reversible charge trapping/detrapping effect. This photoconductive liquid crystal may have a promising possibility and new insight toward practical application for ultrahigh-density information storage and switching devices.