A polymer-dispersed liquid crystal based on a biphenol A diglycidyl ether (E-44) and 4-pentyl-4'-cyanobiphenyl was prepared by a method of polymerized-induced phase separation. Electro-optical transmissions of the biphenol-A epoxy resin dispersed liquid crystal were measured as a function of applied alternating voltage over a range of 0-90 V for a liquid crystal cell gap of about 20 mu m. Influences of heat treating time and content of firming agent on the electro-optical transmissions of the biphenol A diglycidyl ether dispersed liquid crystal were discussed.