A software protection method to protect the software in a host against an unauthorized usage of a memory unit used in software is provided. The software protection method comprises the steps of: starting the operation of the software; declaring the memory unit such that the software takes the control right of the memory unit; generating a status tag of the memory unit; setting the status tag as an initializing status to initialize the memory unit; setting the status tag as an access status to access the memory unit; and setting the status tag as a delete status to forgo the control right of the memory unit.