Abstract: A series of hydrotalcite-like compounds were synthesized, and these compounds had different interlayer ions and various intercalations with different valence inorganic acid radicals and different chain-length organic acid radicals. The effect of the hydrotalcite-like compounds on the thermal stability of PVC were investigated by means of thermal aging oven method, Congo red method and torque rheometer. The results indicated that the thermal stability of PVC was improved by incorporating the rare-earth elements and increasing the quantity of ions in the interlay of the compounds. For the hydrotalcite-like compounds with different valence inorganic acid radicals and organic acid radicals, the compounds intercalated with bivalent acid radicals exhibited the best thermal stability. Moreover, the thermal stability showed an increasing trend at first and then tended to decrease with an increase of the carbon-chain length of organic acids in the hydrotalcite-like intercalation.