The present invention discloses a molding system, more particularly, a shrinking type molding system comprising an outer mold, an inner mold and a first pattern layer. An adjustable gap is formed between the outer mold and the inner mold to contain a work piece therein. Furthermore, the work piece with a pattern structure on the surface thereof can be formed by the first pattern layer. The difference between the present invention and the prior art is that the molding system of the present invention is capable of optionally or simultaneously forming the pattern structure on the inner surface or the outer surface of the work piece, so as to solve the long last problem that not all the surfaces of the work piece could have the pattern structure thereon in the prior art.