Government
Type: Constitutional parliamentary democracy.
Independence: August 6, 1962.
Constitution: August 6, 1962.
Branches: Executive--Governor General (chief of state, representing British monarch), prime minister, cabinet. Legislative--bicameral Parliament (21 appointed senators, 60 elected representatives). Judicial--Court of Appeal and courts of original jurisdiction.
Subdivisions: 14 parishes, 60 electoral constituencies.
Political parties: People's National Party (PNP), Jamaica Labour Party (JLP), National Democratic Movement (NDM), United Peoples Party (UPP).
Suffrage: Universal at 18.

Government of Jamaica
The 1962 constitution established a parliamentary system based on the U.K. model. As chief of state, Queen Elizabeth II appoints a governor general, on the advice of the prime minister, as her representative in Jamaica. The governor general's role is largely ceremonial. Executive power is vested in the cabinet, led by the prime minister.

Parliament is composed of an appointed Senate and an elected House of Representatives. Thirteen Senators are nominated on the advice of the prime minister and eight on the advice of the leader of the opposition. General elections must be held within 5 years of the forming of a new government. The prime minister may ask the governor general to call elections sooner, however. The Senate may submit bills, and it also reviews legislation submitted by the House. It may not delay budget bills for more than 1 month or other bills for more than 7 months. The prime minister and the cabinet are selected from the Parliament. No fewer than two nor more than four members of the cabinet must be selected from the Senate.

The judiciary also is modeled on the U.K. system. The Court of Appeals is the highest appellate court in Jamaica. Under certain circumstances, cases may be appealed to the Privy Council of the United Kingdom. Jamaica's parishes have elected councils that exercise limited powers of local government.
source: http://www.state.gov