Abstract: For the first time this paper describes cryptalgalaminates which occur in substantial amounts in non-fossiliferous Middle Cambrian carbonate rocks from the Dongyue district, Hubei. These cryptalgalaminates of different ages and diverse morphologies are closely related with sedimentary environments, thus may be interpreted as a good facies indicator. The discovery of the cryptalgalaminates helps dispel the misunderstanding that the Middle Cambrian strata in the study area are ascribed to the deeper-water sediments, and contributes to the study of the tectono-palaeogeographic changes in the Qinling area during Middle Cambrian time.