Abstract: A digital content protection method applied in a digital rights management (DRM) system is provided. A software identification certification authority issues an identification certification for the player and the user agent and embeds a verification program in the digital content provided by a content provider. When an end user executes the digital content, the verification program will be started to verify the validity of the player and the user agent. When all elements are verified, the user agent can control the player to execute the digital content according to the definition of the right permission to protect the right and interest for the content provider.