Abstract: The conditions of the Treharoses extraction from the bakers active dried yeast were studied．With experiments the following conditions wore selected：alcohol concentration 50％． temperature 80℃，the ratio between yeast and alcohol 1：15 Afterthis the solution were modified with ultrathin decolourizing carbon，ion exchange Then treharoses is crystallized with 95％ alcohol，and the crystallized conditions were：temperature 40℃，the ratio between solution and alcohol 1：4．

Key words: Treharose Active dried yeast Extraction