Abstract: A case assembly includes a first case, a second case, a moving mechanism and a block. The first case has an inner surface and a groove located at the inner surface. The second case includes a main part disposed on the first case and a fixing part disposed on the main part. The moving mechanism is pivoted to the inner surface. The block is pivoted to another end of the moving mechanism. The block is slidable between a fixed position and a detached position. When the block is located at the fixed position, the block restricts the fixing part so as to assemble the second case and the first case together. When the moving mechanism drives the block to the detached position, the fixing part is not restricted by the block, and the moving mechanism forces a part of the second case to separate from the first case.