Soil tillage practices have been shown to have significant influence on microbial activity and community structure through changing soil chemical and physical properties, and as a further consequence on sequestration of soil organic carbon (C). Analysis of soil amino sugar C helps us further understand the underlying microbial processes mediating soil organic carbon stabilization and turnover in soils under different tillage practices. Effects of no-tillage (NT) vs. conventional tillage (CT) over 7 years on the accumulation of amino sugar C in the plow layer (0~20 cm) in black soil of a 7–year-long experiment in Northeast China were analyzed. It was found that NT significantly increased the content of total amino sugar C in the whole plow layer ( p <0.05), especially in the top soil (0~5 cm) by 94.7% as compared with CT. The finding indicates that NT favors sequestration of microbial derived organic C in the black soils under study. The amounts of amino sugar C’s of different sources all increased in NT over CT in a varying degree. At all the three soil depths, the ratios of glucosamine to muramic acid were significantly higher in NT soils (6.9~7.3) than in their respective CT soils (4.7~5.4) mainly because of more pronounced enrichment of gulcosamine. The enrichment of fungal-derived glucosamine suggests that fungi have gradually grown into dominance in the NT agroecosystems, thus leading to higher soil organic C storage in the soils.