This invention discloses a method of protecting copyright of a digital video work by using a digital password technology and a digital watermark technology to prevent the unauthorized use of a digital video work. Such method adds a password into two color matrixes of such video work in advance, so that when such video work is published on the Internet, it can be played by a specified player. As long as a user enters the correct password into the specified player, a full visual effect of such video work can be obtained. If other players are used to play such video work, only partial gray-scale visual effect can be obtained. Users must request or buy a specific player and a password from the distributor of such video work to play the complete information to prevent piracy.