(1) l-Threose diacetamide has been obtained by the Wohl’s method of degrading sugars from l-xylose which was prepared from d-sorbitol by Vargha’s method. (2) It has been found that this l-threose diacetamide melts at 164–165° (corr.) and has a specific dextrorotation of +10.8° in water. These properties are in good harmony with R. Hockett’s value and sign, and do not agree with those of Deulofeu. (3) This l-threose diacetamide has been submitted to hydrolysis with 1/3 N and 1/10 N sulphuric acid respectively. From these experiments the equilibrium specific rotation of l-threose in dilute sulphuric acid was determined to be +13.1°. It has a little higher value (about 0.6°) compared with Hockett’s d-isomer, but it is now clear that the pure l-threose expected by Hockett has been obtained.