A method for authorizing and accounting a host with multiple addresses in IPv6 Network includes: authorizing multiple addresses of the host respectively; charging the multiple addresses authorized of the host respectively. A system based on the above method includes: a network access server, for transmitting accounting information of multiple addresses of a host upon receiving authorization information; an Authentication, Authorization and Accounting (AAA) server, for authorizing the multiple addresses of the host respectively, and transmitting the authorization information to the network access server; receiving the accounting information transmitted from the network access server, and charging the multiple addresses according to the accounting information respectively. Consequently, it may be implemented to authorize different multiple addresses of the host and charge the different multiple addresses according to different charging rates respectively in an IPv6 network in accordance with embodiments of the present invention.