These Transactions provide a record of the formal organisational and administrative proceedings of the IAU XXVIII General Assembly which took place in Beijing, China, in August 2012. They include the admission of new members, the Resolutions passed, and an account of the regular Business Meetings of the Executive Committee and the Divisions, Commissions and Working Groups. Of particular note, a new divisional structure for the IAU was approved and a new Division on 'Education, Outreach and Heritage' created. Also included in this volume is the welcome address given by Xi Jinping, then Vice-President and now President of the People's Republic of China. Over 3200 registered attendees enjoyed a rich scientific programme of 8 Symposia, 7 Joint Discussions and 18 Special Sessions. Proceedings of the IAU Symposia are published in a separate series, and those of the Invited Discourses, Joint Discussions and Special Sessions feature in Highlights of Astronomy, Volume 16.