A 9.2 m thick dolostone unit is present in the middle Niutitang Formation (lower Cambrian), which is characterized by black shale, in the Zhijin region of central Guizhou province. Small-scale scour structures, trough cross bedding, and lower angle cross bedding and horizontal bedding in this dolostone unit indicate deposition in a carbonate shoal facies during the Niutitang time, rather than low energy reduc- ing environments. In addition, the occurrence of purple mudstone underlying basal Niutitang black shale and siltstone in the overlying Mingxinsi Formation suggest that the lower and upper Niutitang Formation were also deposited in relatively shallow water depths. The presence of dolostone in the Niutitang Forma- tion in the Zhijin region of Central Guizhou shows that there are at least two sea-level changes in the Niuti- tang depositional stage, and provides new data constraining global sea-level changes in the Cambrian Period.