An optical disk, optical disk player and optical disk playing method are disclosed, wherein the optical disk is used to play in coordination with the downloaded contents. The optical disk has a public key used to verify whether the downloaded content is authenticated. The optical disk player comprises a reading-out means, a network interface and a verifying module, in which the reading-out means is used to read-out the content and the public key of the optical disk; the network interface is used to receive the downloaded content; and the verifying module is used to verify whether the downloaded content is authenticated according to the public key read-out from the optical disk. The optical disk playing method consists of reading-out the content and the public key of the optical disk, downloading the content, then verifying the downloaded content according to the public key read-out from the optical disk, in order to confirm whether the downloaded content is authenticated.