In an antiferroelectric liquid crystalline SmCA* phase, the helical structure of molecular alignment depends strongly on temperature. It is well known that in the SmCA* phase of optically pure MHPOBC, the helical pitch increases to infinity and then the right or left helical handedness changes to the other as temperature decreases after the phase transition to the SmCA* phase. In this study, we have investigated the temperature dependence of the helical structure of polymer-stabilized antiferroelectric liquid crystals (PS-AFLCs) in terms of circular dichroism (CD) and optical rotatory power (ORP), and discuss the effect of introducing the polymer network into the AFLC medium upon the helical structure. It is found that the both of helical pitch and handedness can be fixed by polymer stabilization over a wide range of temperature.