A rarely Early Carboniferous metazon framework is unusually well developed in Tianlin region, Guangxi Province, China. This reef is constructed mostly by Diphyphyllum, Siphonodendron, Lithostrotion and Syringopora. The individual of frame-building corals occupied more space niche by clonal budding and bending growth avoiding obstacle. Whereas, in order to achieving successful competition，the growth strategy of groups was overtopping. The reef growed continuously, there was no significant discontinuity and cyclicity. But there are some differences among the biological assemblages of reef-building coral during the frame-building period. Three continuous biological assemblage units can be identified, that are Diphyphyllum assemblage units, Siphonodendron-Lithostrotio assemblage units and Diphyphyllum-Syringopora assemblage units. Six microfacies types may be distinguished, including a little-bioclast wackstone, calcareous algae wackstone, bioclast packstone, muddy grainstone, coral framestone and foraminifera bioclast grainstone. The sedimentary facies model transfers from the depth open carbonate platform facies, shallow open carbonate platform facies, coral reef facies, inner carbonate platform slope facies, to intraplatform shoal facies. The facies indicate that the sedimentary environment was a lowering of relative sea level, water-shallowing and enhanced hydrodynamic force.