<;P>;PROBLEM TO BE SOLVED: To provide a pipeline structure stably keeping the environment suitable for propagation of benthic organisms and heightening the variety of species living in a coastal zone, and to provide a complex thereof. <;P>;SOLUTION: The pipeline structure 10 is installed in the coastal zone, having a water area in which the water level changes vertically and forms a habitat for the benthic organisms by utilizing the water level change, and is equipped with a granule-storing part 1 which is equipped with a pipe line, having one terminal that communicates with an upper opening 10a, positioned in between the maximum water level and the minimum water level of the coastal zone, and having a shape directed downward from the one terminal to a prescribed position, and thereafter, being directed upward from the position; and a communicating pipeline 8 for communicating the other terminal of the granule-storing part 1 with a lower-side opening 10b formed at a position lower than the upper-side opening. <;P>;COPYRIGHT: (C)2009,JPO&INPIT