Based on lots of study results and geologic evidence, the Jiangnan belt has been considered as a Neopro-teroic collision erogenic belt. Recently, some researchers found Late Paleozoic radiolarian cherts in Neoprotero-zoic ophiolitic melange blocks in the Northeastern Jiangxijthus they proposed that the cherts in the ophiolitic melanges are at least the Late Paleozoic product. From this viewpoint, they further suggested that the Jiangnan craton may have broken up and that a Paleozoic ocean, called the "Banxi Ocean", occurred in this region. According to synthetic researches on the lithology, geochemistry and so on, the authors suggest that the radiolarian cherts belong to continental-margin shallow-water sediments, and the REE patterns of the cherts do not support the viewpoint of deep-water environment above oceanic crust. The strong Indosinian tectonic event may have caused these rocks to be displaced at first and then mixed with Neoproterozoic ophiolitic rocks.