A method for exporting permission is provided to solves the problem that the permission can not be exported multiple times among several DRM systems in the prior art; the method includes that: determining that a license is permitted to be exported to a system that a target device belongs to; determining whether an export permission in the license is permitted to be exported; and exporting the export permission in the license to the target device if the export permission in the license is permitted to be exported, which enables the target device to export the license to another device. A terminal apparatus, a server and a communication network are also disclosed.