Studies the phase behavior and electric-optical properties by mixed the negative nematic liquid crystal and chiral components. It contains 3 kinds of Ch phase and M phase. Scattering and transparent states can achieved by changes frequency or field. We also discuss the influence of the content of chiral component for mixed liquid crystal and optical property. Besides join the positive nematic liquid crystal again form the compound department of liquid crystal of 3 compositions, discover when change electric field can reach two stable effects, can with homeotropic, focal conic and planar. We hope applied in electric field or frequency control cause the rapid fast change of light transmittance reach the function of light-values or shutters.