In order to investigate the influence of tobacco powder of different particle sizes on the quality of tobacco materials in electrically heated tobacco products (eHTPs), slurry process reconstituted tobacco was prepared by using tobacco powder of different particle sizes (180 - 380 mesh) on the basis of a home-made experiment platform for slurry process reconstituted tobacco. The surface microstructure and thermo-gravimetric characteristics of the prepared reconstituted tobacco were characterized by scanning electron microscope and simultaneous thermal analyzer, respectively. The smoke release amounts of eHTPs with tobacco materials made from tobacco powder of different particle sizes were qualitatively analyzed by e-cigarette smoke analyzer. The results showed that: 1) When the particle size of tobacco powder was larger than 280 mesh, the reconstituted tobacco featured uniform tobacco powder distribution and compact microstructure. 2) The thermal weight loss characteristics of the reconstituted tobacco could be analyzed by the thermochemical analysis method within the range of 0 to 600 °C. The major thermo-gravimetric stage was from 40 to 370 °C, wherein the mass loss of reconstituted tobacco was higher than 50 %. 3) In the heating process of reconstituted tobacco, the smoke release amount closely negatively correlated to the particle size of tobacco powder, namely the release amount increased with the decrease of the particle size. The results of this study provide a technical support for tobacco material preparation and new product development of heated tobacco products.