Each Party to the Convention and its Kyoto Protocol is represented at sessions of the Convention bodies by a national delegation consisting of one or more officials empowered to represent and negotiate on behalf of their government.

Based on the tradition of the United Nations, Parties are organized into five regional groups, mainly for the purposes of electing the Bureau, namely: African States, Asian States, Eastern European States, Latin American and the Caribbean States, and the Western European and Other States (the "Other States" include Australia, Canada, Iceland, New Zealand, Norway, Switzerland and the United States of America, but not Japan, which is in the Asian Group).

The five regional groups, however, are not usually used to present the substantive interests of Parties and several other groupings are more important for climate negotiations.

Developing countries generally work through the Group of 77 to establish common negotiating positions. The G-77 was founded in 1964 in the context of the UN Conference on Trade and Development (UNCTAD) and now functions throughout the UN system. As at May 2014, there are 133 members in the Group. The country holding the Chair of the G-77 in New York (which rotates every year) often speaks for the G-77 and China as a whole. However, because the G-77 and China is a diverse group with differing interests on climate change issues, individual developing countries also intervenes in debates, as do groups within the G-77, such as the African States, the Small Island Developing States and the group of Least Developed Countries.

The Small Island Developing States (SIDS) is a coalition of some 40 low-lying islands, most of which are members of the G-77 that are particularly vulnerable to sea-level rise. SIDS countries are united by the threat that climate change poses to their survival and frequently adopt a common stance in negotiations. They were the first to propose a draft text during the Kyoto Protocol negotiations calling for cuts in carbon dioxide emissions of 20% from 1990 levels by 2005.

The 48 countries defined as Least Developed Countries by the UN regularly work together in the wider UN system. They have become increasingly active in the climate change process, often working together to defend their particular interests, for example with regard to vulnerability and adaptation to climate change. Previously there were 49 countries in the LDCs Group. However, in 2014 Samoa graduated from the LDCs.

The 28 members of the European Union meet in private to agree on common negotiating positions. The country that holds the EU Presidency - a position that rotates every six months - then speaks for the European Union and its 28 member states. As a regional economic integration organization, the European Union itself can be, and is, a Party to the Convention. However, it does not have a separate vote from its members. Croatia is the latest country to join the European Union in 2013.

The Umbrella Group is a loose coalition of non-EU developed countries which formed following the adoption of the Kyoto Protocol. Although there is no formal list, the Group is usually made up of Australia, Canada, Japan, New Zealand, Kazakhstan, Norway, the Russian Federation, Ukraine and the US.

The Environmental Integrity Group (EIG), formed in 2000, comprises Mexico, Liechtenstein, Monaco, the Republic of Korea and Switzerland.

The Arab Group is comprised of 22 member states namely Algeria, Bahrain, Comoros, Djibouti, Egypt, Iraq, Jordan, Kuwait, Lebanon, Libya, Morocco, Mauritania, Oman, Palestine, Qatar, Saudi Arabia, Somalia, Sudan, Syria, Tunisia, United Arab Emirates, Yemen.

Several other groups also work together in the climate change process, including countries from the Organization of Petroleum Exporting Countries (OPEC), a group of countries of Central Asia, Caucasus, Albania and Moldova (CACAM), the Cartagena Dialogue, the Independent Alliance of Latin America and the Caribbean (AILAC), the BASIC Group (Brazil, South Africa, China India), the Like Minded Group, the Coalition for Rainforest Nations and the Bolivarian Alliance for the Peoples of our America (ALBA in Spanish).