The Conference of the Parties (COP) is the prime authority of the Convention. It is an association of all member countries (or "Parties") and usually meets annually for a period of two weeks. These sessions are attended by several thousand government delegates, observers, and journalists. As the COP Presidency rotates among the five recognised UN regions - that is, Africa, Asia, Latin America and the Caribbean, Central and Eastern Europe and Western Europe and Others – there is a tendency for the venue of the COP to also shift among these groups.

The Conference of the Parties evaluates the status of climate change and the effectiveness of the treaty and it is responsible for keeping international efforts to address climate change on track. It reviews the implementation of the Convention and examines the commitments of Parties in light of the Convention’s objective, new scientific findings and experience gained in implementing climate change policies. A key task for the COP is to review the national communications and emission inventories submitted by Parties. Based on this information, the COP assesses the effects of the measures taken by Parties and the progress made in achieving the ultimate objective of the Convention.