Abstract: In order to investigate the puff-by-puff release behaviors of aerosol components of 2 types of e-cigarettes with different atomization mechanisms, two e-cigarettes adopting a resistive coil and another with an ultrasonic atomization were smoked by a modified rotary smoking machine. The aerosols released from the first 15 puffs of the two e-cigarettes were trapped on filters on a puff-by-puff basis. The variations of the aerosol collection mass(ACM), nicotine releases, and the releases of 1, 2-propylene glycol, glycerol and formaldehyde and their ratios with ACM were analyzed. The results showed that: 1) The stability of each aerosol index from the e-cigarette adopting resistance wire atomization was better than the one adopting ultrasonic atomization with the proceeding puffs. 2) Due to the dual effects of ultrasonic oscillation and atomizer heating, the ACM and releases of 1, 2-propylene glycol, glycerol and nicotine increased first, then stabilized gradually with the proceeding puffs. 3)The ratio of 1, 2-propylene glycol in ACM was higher and that of glycerol was lower for initial puffs for the ultrasonic e-cigarette. 4)Because the atomizer temperature of the ultrasonic e-cigarette was lower than that of the resistance wire, the formaldehyde release and its ratio in ACM were less for the ultrasonic e-cigarette, reaching one fifth for the ratio of formaldehyde in ACM.