Manufacturing of polysilicon by chemical vapor deposition from SiHCl 3 in a fluidized-bed reactor was studied. The effects of reaction temperature, H 2 /SiHCl 3 ratio, gas velocity, and seed particle loading were evaluated. The outlet gas composition was analyzed by gas chromatography. The physical features of the product particles were determined by scanning electron microscopy and laser particle size analyzer. Well-grown product particles were obtained. The temperature and H 2 /SiHCl 3 ratio significantly affected conversion, yield, and selectivity, which were less affected by gas velocity and seed particle loading at higher temperatures. The surface reaction kinetics determined the product yield only at lower temperatures, and thermodynamic equilibrium was approached at temperatures above 900°C.