To provide an assembly toy in which appearance after assembling cannot be viewed until the last to provide unexpectedness.

The assembly toy includes a decorated body 11 with a head part 12, a decorating body 30 attachable to the decorated body 11, and a box body 20 to house the decorating body 30. An insertion part 13 is formed outward projecting from the head part 12 of the decorating body 11. An insertion hole 31 into/from which the insertion part 13 is insertable/extractable is formed on the decorating body 30. An opening part 21 is formed in the box body 20 so that the insertion hole 31 of the decorating body 30 is exposed. When the insertion part 13 is inserted into the insertion hole 31 and then the box body 20 is removed, the decorated body 11 and the decorating 30 are connected together to become extractable.