Abstract: A biodegradable stent includes flexible connection units comprising extensions and a base perpendicular thereto. The base includes ring members coupled by links. The extension includes a first end, a ring element at a second end and a hollow double-convex shaped intermediate section. The width of the intermediate section is greater than an inner diameter of each of the ring members and each of the ring elements. The ring elements of the extensions of a first connection unit are inserted through the ring members of the extensions of a second connection unit to assemble the first and second connection units. The connection units are connected and securely joined to form a contracted tubular stent. The base of the second connection unit is superimposed with the second end of the first connection unit. In such a manner the stent is expanded.