Abstract: A case assembly includes an upper case, a lower case, a pivot, a first shaft, a second shaft, and a stopper. The pivot is pivotally connected to the lower case, such that the upper case is able to rotate with respect to the lower case. The stopper has a shaft hole, a guiding slot hole, and a fixing slot hole. The shaft hole is disposed at one end of the stopper, and fixing slot hole is disposed at the other end of the stopper. The fixing slot hole communicates with the guiding slot hole. The first and the second shafts respectively insert into the shaft hole and the guiding slot hole. When the upper case rotates with respect to the lower case, the second shaft is stuck in the fixing slot hole from the guiding slot hole.