IPv6 is the best protocol to replace IPv4, solve the jam of Internet facing nowadays, provide better service and development for next Internet because there is a huge address space, hiberarchy of addressing architecture, high-speed route, better security, better support for mobility and QoS. The document discourses at great length on the addressing architecture of IPv6, the addressing types of IPv6 and their connections with interface, the addressing model of IPv6 and the representation of detailed format and brief format for the IPv6's addressing, addressing prefixes and addressing types. And this specification discusses the addressing format, the addressing range and their uses of unicast, anycast and multicast. The paper has guide effect on constructing network of IPv6.