Abstract: The quality of Daqu plays a decisive role in the yield and quality of Baijiu. Comparisons of medium-high temperature superior,ordinary and inferior-quality Daqu provided by SheDianLaoJiu Co.,Ltd with six months storage in the same room. The quality differences of Luzhou-flavor medium-high temperature liquor Daqu were comprehensively analyzed through the detection of sensory characteristics,physical and chemical indexes and total microorganisms. The results showed that the total number of bacteria,molds and yeasts in the superior-quality Daqu was higher than that of the ordinary-quality and the inferior-quality Daqu,and the inferior-quality in the total number of microorganisms was the least. Between different samples,the total number of microbes significant difference(P<0.05). In the physical and chemical indicators,the superior-quality Daqu was relative to the ordinary-quality and the inferior-quality Daqu,and its moisture acidity,saccharification power,liquefaction power,fermentation power,and amino acid nitrogen were all higher,while starch content was lower. At the same time,there was no significant difference between different samples in water content and starch content(P>0.05),and other physical and chemical indexes were significantly different(P<0.05).This indicated that superior-Daqu could still be used as saccharification starter for high quality Baijiu,while inferior-Daqu could no longer be used.