The differences and variation rules between parts of Daqu with medium and high temperature were studied by analyzing the biochemical indexes and fermentation process.The results showed that the esterification ability was the highest at the centre of Daqu,the microbial number and other enzymes were the highest on the surface of Daqu; the moisture and acidity were the highest in the medial position of Daqu,and other properties lied mediacy. During the main fermentation period, the fermentation power increased rapidly; the saccharifying power droped rapidly at the centre of Daqu;but the moisture decreased quickly on the surface of Daqu. During the tidal-fire period, the fermentation power droped rapidly;the esterification ability and acidic protease activity increased; the acidity was gentle; but the moisture continues to decrease on the surface of Daqu. During the fire period,the enzyme activity and microbial numbers were both low; the water and acidity began to decrease at the centre of Daqu. After the fire period, the esterification ability and activity of acid protease rose again, so did the glycosylation ability at the centre of Daqu. During the curing period, the saccharifying power continued to rise, the esterification ability and activity of acid protease were slowly decreasing, the moisture was further reduced at the centre of Daqu.