A locking mechanism is provided. The locking mechanism includes a base, a connecting rod, a fastener, and a linking member. The connecting rod and the fastener penetrate the base and are rotatable relative to the base. The connecting rod and the fastener are disposed parallel to each other. The linking member is connected to the connecting rod and the fastener, and is configured to link up the connecting rod and the fastener. Accordingly, the locking mechanism may be suitable for an expansion device with a specific size, and therefore the performance and the design flexibility of the electronic apparatus may be enhanced.