Based on the study of radiolarian abundance

fossil differentiation

genus and species assemblage and bioecologic texture

the main indicators for recognizing the radiolarian bioecologic environment were discussed.The radiolarian habitats of South China during Hercynian Indosinian could be classified into 5 types:(1)shallow sea habitat type of 50-200 m water depth

(2)sime deep sea habitat type of 200-1 000 m water depth

(3)deep sea environment with more than 1 000 m water depth

(4)restrict rift sea habitat type of 50-200 m water depth

and(5)connected rifted sea habitat type of more than 200 m water depth. The radiolarian could be divided into three succession cycles according to the evolution of radiolarian assemblages in every stratigraphic unit.The radiolarian succession cycle of Middle Devonian-Early Carboniferous reflects a respreading process of the relict ocean trough.The Middle Permian radiolarian succession shows a open rifted oceanic environment.The radiolarian succession cycle of Late Permian-Middle Triassic indicates a development process of restricted rift trough

→

connected rift trough

→

open deep ocean .