Liquid crystalline (LC) polyphenylene derivatives, such as poly(para-phenylene) (PPP), poly(meta-phenylene) (PMP), poly(meta-biphenylene) (PBP), and poly (meta-terphenylene) (PTP) derivatives, were synthesized through substitution of fluorine-containing chiral LC groups into side chains, with an aim to develop ferroelectric LC (FLC) conjugated polymers. All the polymers, except PTP, showed enantiotropic liquid crystallinities, where several types of mesophases were observed in both heating and cooling processes. Among them, PPP and PMP derivatives showed chiral smectic C (S-C*) phases responsible for ferroelectricity. In fact, they exhibited quick response to electric field, in spite of high viscosities inherent to polymers, giving rise to switching times of less than 1 s between two S-C states with reversely directed alignment. Hysteresis loops between the polarization and electric field were also observed for PPP and PMP. The spontaneous polarization (PS) of PMP remained unchanged even after the electric field became zero, affording the residual polarization (PR) whose value was the same as that of P-S. This indicates that PMP has a prospective memory function based on FLC nature. The present study is the first report for realizing a quick switching in macroscopic alignment using electric field and also for generating a potential memory function in pi-conjugated polymers. It is elucidated that unusual polymer main chains such as polyphenylenes can be used to prepare new ferroelectric polymers. (C) 2008 Wiley Periodicals, Inc.