Abstract: A folding mechanism includes two retractable folding assemblies. A first retractable folding assembly includes a first base member, two friction members, two first dual-pivotal plate units, two first fixation plate units and a first pulling member. The two friction members are mounted to opposing ends of the first base member. The first dual-pivotal plate unit is symmetrically pivotally connected with opposing sides of the first base member. The first fixation plate unit is individually pivotally connected with the first dual-pivotal plate unit. The first pulling member is mounted at the first base member. A second retractable folding assembly is structurally resembled to the first retractable folding assembly. A movable buckle unit is further included to buckle or release springily two dual-pivotal plate units of the second retractable folding assembly.