The chassis assembly comprises a main housing, a latching module and a cover plate. The main housing has at least a side plate which has at least one track portion on the inner surface thereof. The latching module is slidably assembled to the side plate and includes a first locking member slidably assembled on the track portion and having at least one retaining portion; an elastic member connected between the latching module and the side plate; and a second locking member assembled with the first locking member and sandwiching the side plate with the first locking member. The cover plate is detachably assembled to the main housing, and includes at least one stator portion corresponding to the retaining portion.