A novel method for Na2SnO3 preparation from SnO2 and Na2CO3 roasted under CO-CO2 atmosphere in a solid state has been successfully developed. In this study, the formation kinetics of Na2SnO3 was investigated. The formation of Na2SnO3 was controlled by the first-order interfacial chemical reaction at 800 degrees C under 10 vol% CO content; as the temperature increased to 850 degrees C-900 degrees C, it was controlled by the three-dimension (Ginstling and Brounshtein) diffusion through the product layer at the early reaction stage. The rate constant increased with the increasing of temperature. Furthermore, the rate controlling characterizations of three-dimension diffusion were also discussed. (C) 2017 Elsevier B.V. All rights reserved.