Abstract: The synergistic effects of maltitol, mannitol, and pentaerythritol with calcium/zinc thermal stabilizer in PVC were compared using Congo red test, conductivity measurement, thermogravimetric analysis, thermal aging method. The results showed that the thermal stabilization time of PVC containing calcium/zinc complex with maltitol was 46 min, 4 times as that of pure calcium/zinc system. From the conductivity measurements the induction time of the system was longer up to 43.81 min. Moreover, the thermal weight loss in the first stage was 48.13% from the thermo gravimetric analysis. All the calcium/zinc complex systems with polyols used in this work showed the better long-term thermal stability than that with mannitol or pentaerythritol.