Disclosed in the invention is a connector structure that is used on a mother board for holding a central processing unit of cartridge type or card type. The connector structure comprises two connector halves. Each connector half has retaining slots and elongated notches formed on the upper portion thereof. Such an arrangement makes the connector structure adapted for holding cartridge type central processing units. The connector half has an incompletely connected retaining protrusion on one side. The retaining protrusion extends obliquely and inwardly and has locking means disposed on the lower end and an upwardly extending moving lever arranged on the outside of the locking means. The above arrangement makes the connector suitable for holding a card type central processing unit. Each connector half is composed of a stationary piece pivotally connected with a movable piece. Thus the connector can be folded when not in use to decrease the space it takes. Alternatively the connector half also can be integrally molded.