A cylindrical lock includes an outer operational device mounted to an outer side of a door, an inner operational device mounted to an inner side of a door, and a latch device between the inner and outer operational devices. The inner operational device includes an inner spindle and a locking driving device mounted in the inner spindle and connected to a burglarproof system. The locking driving device includes a motor for moving a driving member to perform a locking function setting or an unlocking function setting. Thus, the cylindrical lock in the locking state will not turn into the unlocking state even if power failure occurs. Likewise, the cylindrical lock in the unlocking state will not turn into the locking state even if power failure occurs.