Abstract: A stage structure disposed to a vehicle which includes a head portion and the stage structure has a base connecting to the head portion, two first posts and two second posts respectively disposed to four corners of the base and a top cover mounted to the four posts wherein one side of the top cover is pivotally connected to two of the posts in a longitudinal direction of the base, a lower supporting board connected between each pair of two posts for a first cylinder disposed thereon which connects to a mediate part so as to lift the other side of the top cover, a first frame and a second frame respectively and retractably disposed below an under surface of the top cover, each of the first frame and the second frame respectively connected to a second cylinder and a third cylinder on the top cover, a third frame pivotally connected to the second frame, an extending base respectively pivotally connected to each one of two sides of the base such that a stage can be formed by extending these frames and extending b