A two stage quick-release structure includes a first tubing member, a second tubing member, a first pivoting portion, a first buckling portion, an elastic hook and a safety fastener. When the user assembles the foldable bicycle for bicycling, the first tubing member is rotated to connect with the second tubing member via the first pivoting portion, so that the elastic hook correspondingly buckles with the first buckling portion to form a first stage buckle; then, the safety fastener is rotated to correspondingly buckle with the elastic hook so as to form a second stage buckle. The two stage buckle contributes the assembling of the foldable bicycle with ease and convenience. Furthermore, via the two stage buckle structures, the connection between the front bicycle frame body and the rear bicycle frame body are tightly secured.