A lock assembly has a body, a latching device, a linking device and a locking mechanism. The linking device is connected to and driven by the latching device. The locking mechanism is moveably mounted in the body and has a bolt base, a pushing element, a lever element and a locking bolt. The bolt base is mounted slidably in the body. The locking bolt is slidably mounted on the bolt base and is driven to retract into or completely extends out from the body with the transmission of the pushing element and the lever element.