The present application relates to a composition for 3D printing, the composition containing a thermosetting compound, 1-40 parts by weight of a thermoplastic resin on the basis of 100 parts by weightof the thermosetting compound, and magnetic particles. In addition, the present application relates to a 3D printing method using the composition and a three-dimensional shape comprising the same, and provides a composition for 3D printing, which has precision and excellent curing stability and is capable of realizing a three-dimensional shape.