The Bikou volcanic terrane is predominated by tholeiitic marine lavas, with lower initial ratios of Sr and Nd, 0.701 248～0.704 413 and 0.511 080～0.512 341 respectively. Analyses also showed that most samples have negative εNd, which indicates that magma was probably derived from the mantle, while those with positive εNd perhaps resulted from magmatic contamination. In addition, rocks have significantly higher 207Pb and 208Pb. REE patterns and trace element spider diagrams indicate that magma generated by partial melting gave rise to some extent of differentiation during its evolution. Consequently, LREE and LILE demonstrated variation from depletion to enrichment.Besides, Basic lavas from the Bikou volcanic terrane showed the same characteristics as those from arcs in the background of subduction and collision with the consideration of ratios of Th/Yb, Th/Nb and Hf/Th. New evidence showed that the Hengdan group is a turbidite terrane filled in a forearc basin, and both the Bikou and the Hengdan groups construct an arc-basin system developed on the north margin of Yangtze plate. SHRIMP ages indicated that the arc-basin system developed in the Neoproterozoic.