Food additives have been used for inhibiting microbial growth in the food industry. Basal stem blockage caused by microorganisms can hasten flower senescence. The objective of this study was to investigate the effect of food additives on quality and vase life of Dendrobium ‘Red Sonia’ cut flowers. Inflorescence were put into vase solutions of potassium carbonate at 1.75 and 2% or sodium carbonate at 1.50, 1.75 and 2%, while distilled water and a commercial flower preservative solution served as the control. The cut flowers were kept at 25°C under constant light intensity of 10 µmol/m2s. Potassium carbonate and sodium carbonate increased bud opening 20-33%, whereas bud opening of inflorescences placed into distilled water and commercial solution were 53.6-63.3%. The commercial solution also increased fresh weight significantly. Inflorescences placed in distilled water had the longest vase life (19.5 days) due to decreased flower dropping. The vase life of inflorescences placed in the commercial solution, potassium carbonate, and sodium carbonate were 14.5, 9-10 and 6-7 days, respectively.