Abstract: In order to investigate the effects of key parameters, including the moisture content, propylene glycol(PG)to glycerin(GLY)ratio and nicotine concentration in e-liquids and the output power of e-cigarette devices, on the releases of aldehydes in aerosol, laboratory-prepared e-liquids were filled into a commercial refillable e-cigarette. The aerosols of 50 puffs were collected from the device, and the releases of formaldehyde, acetaldehyde and acrolein in the aerosols were collected and analyzed by HPLC(High Performance Liquid Chromatography)under the parameters of 55 mL puffing volume, 30 s puffing interval and 3 s puffing duration. The results showed that: 1)Acetaldehyde was mainly from the thermal degradation of PG, formaldehyde was mainly from the thermal degradation of GLY, and acrolein was mainly from the dehydration of GLY at higher temperatures. 2) The releases of aldehydes decreased with the increase of the nicotine concentration in the e-liquids, while increased quickly with the output power of the device. 3) The effect of moisture content in the e-liquids on aldehydes releases was minor.