Methods have been elaborated to determine the course of die enzymatic hydrolyses of some acetylated carbohydrates.The determination of total fructose, reducing sugar and ester bond, according to the methods of Roe, Somogyi-Nelson and Hemin tespectively, apply without correction to acetyl esters (but not to phosphate esters).Acetyl derivatives of glucose were estimated by glucose oxidation following deacetylation, Progressive acetylation of sucrose makes the glycoside bond more resistant to acid hydrolysis.Chromatographic techniques applying to acetylated sugars are described. These include a new sensitive spray for esters.