A keypad system operates in a first mode or a second mode. Each key cap is coupled to each group of adjacent two key switches. Each of first symbols is disposed on each of key caps. Two of each second symbols which is rotated 90 degrees to the first symbols are disposed over each key cap, and each of the two symbols is located over each of the key switches. When a key is actuated in the first mode, a first symbol assigned to the key cap is outputted. When a key is actuated in the second mode, a second symbol located over the actuated key switch is outputted. When there is a display operating with the keypad system, the contents of display can be oriented horizontal to the first symbols in the first mode or horizontal to the second symbol in the second mode.