One 300 m thick core of the late Bashkirian-middle Kasi-movian red algae reef crops out in the Dabu and Huanglongformations at Beibuwan. It is located at shallow SW plat-form margin. Themain constructors are the red algae Parachaetetes and Ung-darella. Reef-dwellers include crinoids and fusulinids. Fivesimilar growth stages, characterized by Parachaetetes and Ung-darella bindstone, can be identified, which are separated by fourgrowth intermissions dominated by dolostones, and the fifthgrowth stage also has some small growth intermissions.