The present invention relates to a deforestation apparatus. The seaside forest composition device of the present invention, a bolt fastening hole for bolt fastening is formed on one side, the bottom support member is seated in the seabed rock or seabed artificial structure, and the bolt is inserted into the bolt fastening hole； A pillar member connected to the bottom support member and protruding upward from the bottom support member； A first pillar through-hole is formed at an upper side thereof, and the pillar member is inserted into and connected to the first pillar through-hole, and the access preventing member is formed in a funnel shape of the lower beam cross section； One side is connected to the pillar member, branched from the pillar member into a plurality of branches, the seedling rope is bound； branch member； is configured to include. According to the present invention, a bottom support member installed in a bolt or the like provided in an existing seabed structure such as an artificial reef installed in a seabed, and upwardly protrudes from the bottom support member, the seedling rope is bound. By installing the pillar members, it is possible to create a sea forest by utilizing the subsea artificial structures already installed, and to prevent the breakfast animal from approaching the seedling rope by installing the access preventing member formed in the funnel shape of the lower light reciprocation on the pillar member. , The bottom surface connected with the floor support member is provided by the angle adjusting means to form a locking projection on the surface of the branch member to prevent the slide of the seedling rope, and to adjust the connection angle between the pillar member and the floor support member. Even in the photographic environment, the pillar member is installed vertically toward the surface of the sea to create a smooth sea forest The pillar member is provided with a connecting means for connecting and installing a plurality of up
