Abstract: In order to analyze the characteristics of ammonia release in heat-not-burn (HNB) cigarette smoke, 7 kinds of HNB cigarettes were chosen to determine total ammonia release, puff-by-puff ammonia release and NH₄⁺ contents by ion chromatography under the ISO suction mode. The correlation between ammonia releases and NH₄⁺ contents was investigated. The results showed that: (1) The ammonia releases of most HNB cigarettes ranged from 1-3 μg/cig; (2) The puff-by-puff ammonia release of most HNB cigarettes increased in the first five puffs, then decreased slightly; (3) The RSD of the last three puffs was lower than that of the first three puffs for most HNB cigarettes; (4)The content of NH₄⁺in the core of the HNB cigarettes was between 6.2-82.3 μg/cig(28.8-392.8 μg/g); (5)There was a significant correlation between ammonia release and ammonium salts in the HNB cigarettes of the same company, but no correlation in those of different companies. The above results demonstrated that: compared with the conventional cigarettes, the ammonia release of most HNB cigarettes was close to that of the fine cigarettes with tar release less than 5 mg per cigarette, and the uniformity of distribution of puff-by-puff ammonia release was better than that of the fine cigarettes; Ammonium salts had effects on ammonia release of HNB cigarettes, but it was not the dominant factor.