Abstract: In order to analyze the structure and emission of fibrous materials (expressed in the emission of silica) in the aerosol of electronic cigarettes (ECs), qualitative and quantitative methods were developed. The diameter and length of fiber in the aerosol of ECs were identified by microscopic analysis and the emission was determined using inductively coupled plasma mass spectrometry. The effect of puffing parameters on the emission of fiber in aerosol was examined by analyzing the emissions produced from four continuous puffing groups (30 puffs per group, 120 puffs in total). The results showed that:1) The developed qualitative method was convenient, easy to distinguish, and accurate. The developed quantitative method was sensitive, accurate, and repeatable. 2) The detection rate of fiber in the aerosol of the tested ECs reached 100%. The diameters of fiber identified in the aerosols of all 15 tested ECs ranged from 7.6 to 28.3 μm. According to the diameter and length of the fiber identified, these were man-made glass fiber materials. 3) The emission of fiber ranged from 47 to 432 μg/200 puffs. 4) The emission of fiber among the four continuous puffing groups showed a general lack of regularity, which suggested that the fiber in the aerosols was released randomly.