The Carboniferous phylloid algal buildups are widespread and well exposed in southern Guizhou. A unique depositional sequence consists of phylloid algal buildups, bioclastic banks and mud facies affected by frequent changes of depositional environments. The phylloid algae that grow on the margin of carbonate platform prefer to live in clean water with medium turbulence. Therefore the phylloid algae must be a narrow spectrum of ecological environment. Adjacent two leaves of phylloid algae rarely are tightly together in the growthform and the spaces between two leaves are often filled with sparry calcite. It indicates that phylloid algae thallus should be a certain tenacity and intensity. The worm may be taked part in the construction of buildup substrate, and they are the pioneer of phylloid algal buildup.