A connector position assurance device (CPA) cooperated with a plug connector to ensure a latch of the plug connector located in a releasing state or a blocked state, includes a base including a downwardly deflectable center arm and a pair of sidewardly deflectable side arms enclosing the center arm in a transverse direction. The bottom surface of the center arm have an engagement protrusion, each side arms have an engagement protrusion which protruding in a transverse direction. The CPA is maintained in a front blocked position or a rear releasing position in the connector to ensure the latch blocked or released.