Abstract: To investigate the effects of extract solution and standard solution on the determination of contents of glucose,fructose,sucrose and maltose in tobacco samples,the stabilities of the four sugars in the extract solutions of water or aqueous sodium hydroxide were compared,and the stability of prepared standard solution was also determined.The results showed that:1) The hydrolysis of sucrose and maltose in extract solutions was effectively inhibited while 0.02 mol/L aqueous sodium hydroxide was used for extracting tobacco samples.The variations of the contents of the four sugars were less than 15% within 16 hours.2) The quantitative accuracy could be ensured with the relative standard deviation of stock solution less than 1% within 30 days when water was used for preparing the standard solution.The contents of glucose,fructose,sucrose and maltose in tobacco could be accurately determined by using aqueous sodium hydroxide solution as the extract solvent and using water for preparing the standard solution.