Abstract: Comparison of the influences of the preparation methods and reaction conditions to the properties of SnO2 powder,especially the specific surface area and the stability under high temperature calcination were performed.SnO2 prepared by precipitation method using NaOH solutions as the precipitating agent in the pH region of 10 and aged at100℃ for 48h had the highest BET surface area of 93.5m2 g-1 after calcination at 500℃ for 4h.The materials maintained a surface area of75.2m2 g-1 after 800℃ and 53.2m2 g-1 after 1000℃ alcination. The sample using NH3 H2O as precipitation agent had the lowest BET surface area calcinied under the above three temperatures.It was shown that using NaOH as precipitation agedt and digestion at high temperature was beneficial to maintain high surface area and good stability under high temperature.One of the reas ons is that the digestion under high temperature reduced the water content in th e hydrous tin oxide gel,so the initial structure of the particle was enhanced du ring the drying and calcining process.The other reason is that the crystallizati on of the initial particles was enhanced during the digestion and the defect on the surface was reduced also,so the sintering due to the surface diffusion was restrained.Further more,washing with ethanol reduced the formation of hardcore agglomeration between the particles,thus improved the stability of the particles under high temperature calcining process.

Key words: SnO₂, Specific surface area, Preparation