To provide a new pyridinium salt type ionic polymer compound derivative capable of actualizing a liquid crystal having a higher torque by an external force such as an electric field, etc., and a high response speed, to provide a method for producing the derivative and also provide a liquid crystal composition.

This pyridinium salt type characteristically has a repeating unit shown by the general formula (R1 is H or methyl; R2 is a 1-22C straight- or branched-chain alkyl; A1 is a 1-18c straight- or branched-chain alkylene; and X is Cl, Br or I), 5,000-30,000 number-average molecular weight and 50,000-600,000 weight-average molecular weight.