A plug terminal includes a main body, a contact portion, and a connecting portion. The contact portion is extending outwardly from the main body, so that the contact portion and the main body form a clamping structure. The contact portion includes a first spring arm and a second spring arm. An inner side of the first spring arm includes adjacent first and second contact protrusions. The second spring arm faces the first spring arm. An inner side of the second spring arm includes adjacent third and fourth contact protrusions. The third contact protrusion faces the first contact protrusion, and the fourth contact protrusion faces the second contact protrusion. Accordingly, when a plug connector is mated with a receptacle connector, the contact area between the connectors can be increased by the plural contact protrusions to guarantee the stability of the electrical contact between plug terminals and receptacle terminals.