PROBLEM TO BE SOLVED: To provide an artificial seaweed or microorganism clinging base capable of efficiently raising natural seaweeds/sea algae undersea by using artificial seaweeds and seaweed-clung ring bodies. SOLUTION: This seaweed or microorganism-clinging base for raising natural seaweeds or sea algae by setting itself undersea includes artificial seaweeds (A) constituted of flexible hollow tubular forms (1), the outer circumferences of which are attached with ring bodies (2, 3 and 4) made of a fibrous product highly tending to cling marine organisms thereto and located at appropriate intervals in the tubular axial direction. The seaweed spores cling to the ring bodies (2, 3 and 4). This base includes a binding element (6) that binds the plurality of artificial seaweeds (A) at their lower ends and a connective member (13) for flexibly connecting the binding element (6) with an anchoring member (25) set at the sea bottom.
