Abstract: To understand the current status of research on additives used in tobacco sticks for heated tobacco products at home and abroad in recent years, the requirements for use of additives, the pyrolysis behavior and the toxicological assessment of additives, and the effects of additives on smoke were reviewed with reference to the safety assessment protocols for additives used by foreign tobacco companies. The conclusions were as follows: 1) Most of the heated tobacco product additives were transferred to the smoke in their original form when heated below 350 ℃. However, the distribution of the pyrolysis products of the additives varied slightly depending on the structural properties of the compounds themselves and the pyrolysis atmosphere, and other factors. 2) Additives could promote the releases of key compounds, such as nicotine, glycerin, and aroma components in the smoke at lower temperatures, and the addition of specific silicates could reduce the releases of harmful components. 3) In the existing additive toxicology studies, commonly used additives, such as glycerin, propylene glycol, and menthol did not increase the cytotoxicity of mainstream smoke in the heated state, but further research should be conducted to determine whether they could reduce smoke toxicity.