The trunks and/or branches of a decoration tree are made of "metal mesh/insulation/metal mesh" sandwiched structure. Ornamental articles are configured to be easily and rapidly inserted into the sandwiched structure to decorate the decoration tree. The two metal meshes are each coupled to one of the two electrodes of an electric power supply. The coaxial pin of each ornamental article is made coaxial to couple to the two metal meshes respectively, so that the ornamental article shines when it has been inserted in the trunks or branches of the tree.