Abstract: The Xikou Formation (T₁x) in the western Fujian is a set of flysch deposits attributed to the basement of a foreland basin and is a rapid sedimentation in deep-marine and turbulent environments of active continental margin. The flysch sequences constitutes a complete series of sedimentary sequences of the foreland basin. The development of the sequences would be closely related with rather mild orogenesis during the early Mesozoic time along the coastal area of the southeast China.