Chaetetids, an important reefbuilding organism, were globally distributed in the Late Carboniferous (Moscovian). Chaetetids reefs reported in China develop mainly in marine limestone of the Benxi Formation (Upper Carboniferous) in the Taizi River Basin, East Liaoning. Chaetetids have a variety of growth forms, such as laminar, tabular, moundy, branched and columnar. Chaetetids reefs were built in the form of tabular cover. In the study area, the reefbuilding process can be divided into three stages, according to the obvious changes of Chaetetids growth forms and the community controlled by Chaetetids in the vertical direction. ①Colonization stage: There were a few Chaetetids which mainly were laminar colonizing the crinoids debris bank. It’s difficult to create the stable environment for other benthic organisms living, because laminar Chaetetids were small and had a weak ability to resist wave. Hence, the community was simple in the stage. ②Flourish stage: Chaetetids were abundant and their growth forms included tabular, columnar, moundy and branched. The reef framework built by tabular Chaetetids or the other forms could create the stable environment for other benthic organisms living. Therefore, the diversity of the community was high in the stage. ③Decline stage: There were few Chaetetids. They occurred as discontinuouslaminar forms colonizing the substrate which composed of crinoids debris. Laminar Chaetetids were fragile and lost ability to improve the environment. In the stage, the community was simple. Overall, Chaetetids growth forms can influence the formation and succession of the community. Chaetetids reef was built as the community evolved. The study focuses on Chaetetids growth forms and reefbuilding process. It can provide a new perspective to understand the reefbuilding mechanism.