Abstract: In order to investigate the influences of cigarette physical specifications on the releases of six harmful components (including phenol, crotonaldehyde, hydrogen cyanide, benzoa pyrene, ammonia and NNK) in mainstream cigarette smoke, the cigarette circumference, cigarette length and cut tobacco width were selected as the variables, and the releases of the six harmful components in mainstream smoke of 120 cigarette samples were studied by multi-factor variance analysis. The results showed that:1) The effect of cigarette circumference on the releases of the six harmful components in mainstream smoke was the greatest, and cigarette length came to be the second. Cut tobacco width impacted on hydrogen cyanide release, while its influences on the other five harmful components were minor. 2) Within the circumference range of 17.0-24.2 mm, the releases of the six harmful components in mainstream smoke positively correlated to the circumference. Within the circumference range of 24.2-27.0 mm, the releases of crotonaldehyde and hydrogen cyanide negatively correlated to the circumference, ammonia release was basically unchanged, and the releases of the other three harmful components positively correlated to the circumference. 3) The releases of all the six harmful components positively correlated to cigarette length. 4) Except that hydrogen cyanide release negatively correlated to cut tobacco width, there was no correlation between the releases of the other five harmful components and cut tobacco width.