Phase transitions of polymer liquid crystals may be induced not only by changes of temperature or polymer concentration．but also by external electric

magnetic or other orientational fields．In this paper the phase behavior of polypeptide liquid crystal solutions

such as PBLG/TCE and PBLG/CHCl3/TFA solutions

was studied in the presence of an external electric field．It was found that the liquid crystal phase was stabilized when the extemal electrical field was applied and the area of liquid crystal phase was broadened．Qualitatively

the experimental results are in good agreement with the theoretical results calculated by a lattice model previously．The information obtained may be used to develop new routes for processing rigid-flexible block copolymers with better mechanical pmpeflies and to construct molecular devices for processing and storing infommtion．